PLT-3383: image proxy support (#7991)

* image proxy support

* go vet fix, remove mistakenly added coverage file

* fix test compile error

* add validation to config settings and documentation to model functions

* add message_source field to post

33 files changed, 6080 insertions, 32 deletions

diff --git a/api/post.go b/api/post.go
index e0cfb720c..192dc0abc 100644
--- a/api/post.go
+++ b/api/post.go
@@ -135,7 +135,7 @@ func saveIsPinnedPost(c *Context, w http.ResponseWriter, r *http.Request, isPinn
 			rpost := result.Data.(*model.Post)
 
 			message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POST_EDITED, "", rpost.ChannelId, "", nil)
-			message.Add("post", rpost.ToJson())
+			message.Add("post", c.App.PostWithProxyAddedToImageURLs(rpost).ToJson())
 
 			c.App.Go(func() {
 				c.App.Publish(message)
diff --git a/api4/channel.go b/api4/channel.go
index f8a069ea0..9801c9dc0 100644
--- a/api4/channel.go
+++ b/api4/channel.go
@@ -386,7 +386,7 @@ func getPinnedPosts(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	} else {
 		w.Header().Set(model.HEADER_ETAG_SERVER, posts.Etag())
-		w.Write([]byte(posts.ToJson()))
+		w.Write([]byte(c.App.PostListWithProxyAddedToImageURLs(posts).ToJson()))
 	}
 }
 
diff --git a/api4/post.go b/api4/post.go
index 7a365845f..80088d9ef 100644
--- a/api4/post.go
+++ b/api4/post.go
@@ -56,7 +56,7 @@ func createPost(c *Context, w http.ResponseWriter, r *http.Request) {
 		post.CreateAt = 0
 	}
 
-	rp, err := c.App.CreatePostAsUser(post)
+	rp, err := c.App.CreatePostAsUser(c.App.PostWithProxyRemovedFromImageURLs(post))
 	if err != nil {
 		c.Err = err
 		return
@@ -66,7 +66,7 @@ func createPost(c *Context, w http.ResponseWriter, r *http.Request) {
 	c.App.UpdateLastActivityAtIfNeeded(c.Session)
 
 	w.WriteHeader(http.StatusCreated)
-	w.Write([]byte(rp.ToJson()))
+	w.Write([]byte(c.App.PostWithProxyAddedToImageURLs(rp).ToJson()))
 }
 
 func getPostsForChannel(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -135,7 +135,7 @@ func getPostsForChannel(c *Context, w http.ResponseWriter, r *http.Request) {
 	if len(etag) > 0 {
 		w.Header().Set(model.HEADER_ETAG_SERVER, etag)
 	}
-	w.Write([]byte(list.ToJson()))
+	w.Write([]byte(c.App.PostListWithProxyAddedToImageURLs(list).ToJson()))
 }
 
 func getFlaggedPostsForUser(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -168,7 +168,7 @@ func getFlaggedPostsForUser(c *Context, w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	w.Write([]byte(posts.ToJson()))
+	w.Write([]byte(c.App.PostListWithProxyAddedToImageURLs(posts).ToJson()))
 }
 
 func getPost(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -206,7 +206,7 @@ func getPost(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	} else {
 		w.Header().Set(model.HEADER_ETAG_SERVER, post.Etag())
-		w.Write([]byte(post.ToJson()))
+		w.Write([]byte(c.App.PostWithProxyAddedToImageURLs(post).ToJson()))
 	}
 }
 
@@ -272,7 +272,7 @@ func getPostThread(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	} else {
 		w.Header().Set(model.HEADER_ETAG_SERVER, list.Etag())
-		w.Write([]byte(list.ToJson()))
+		w.Write([]byte(c.App.PostListWithProxyAddedToImageURLs(list).ToJson()))
 	}
 }
 
@@ -313,7 +313,7 @@ func searchPosts(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
-	w.Write([]byte(posts.ToJson()))
+	w.Write([]byte(c.App.PostListWithProxyAddedToImageURLs(posts).ToJson()))
 }
 
 func updatePost(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -341,13 +341,13 @@ func updatePost(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	post.Id = c.Params.PostId
 
-	rpost, err := c.App.UpdatePost(post, false)
+	rpost, err := c.App.UpdatePost(c.App.PostWithProxyRemovedFromImageURLs(post), false)
 	if err != nil {
 		c.Err = err
 		return
 	}
 
-	w.Write([]byte(rpost.ToJson()))
+	w.Write([]byte(c.App.PostWithProxyAddedToImageURLs(rpost).ToJson()))
 }
 
 func patchPost(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -373,13 +373,13 @@ func patchPost(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	patchedPost, err := c.App.PatchPost(c.Params.PostId, post)
+	patchedPost, err := c.App.PatchPost(c.Params.PostId, c.App.PostPatchWithProxyRemovedFromImageURLs(post))
 	if err != nil {
 		c.Err = err
 		return
 	}
 
-	w.Write([]byte(patchedPost.ToJson()))
+	w.Write([]byte(c.App.PostWithProxyAddedToImageURLs(patchedPost).ToJson()))
 }
 
 func saveIsPinnedPost(c *Context, w http.ResponseWriter, r *http.Request, isPinned bool) {
diff --git a/app/notification.go b/app/notification.go
index 4929d56f4..62aad4c28 100644
--- a/app/notification.go
+++ b/app/notification.go
@@ -270,7 +270,7 @@ func (a *App) SendNotifications(post *model.Post, team *model.Team, channel *mod
 	}
 
 	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POSTED, "", post.ChannelId, "", nil)
-	message.Add("post", post.ToJson())
+	message.Add("post", a.PostWithProxyAddedToImageURLs(post).ToJson())
 	message.Add("channel_type", channel.Type)
 	message.Add("channel_display_name", channelName)
 	message.Add("channel_name", channel.Name)
diff --git a/app/post.go b/app/post.go
index 192c2effb..bf4725e77 100644
--- a/app/post.go
+++ b/app/post.go
@@ -4,6 +4,11 @@
 package app
 
 import (
+	"crypto/hmac"
+	"crypto/sha1"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -309,7 +314,7 @@ func (a *App) SendEphemeralPost(userId string, post *model.Post) *model.Post {
 	}
 
 	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_EPHEMERAL_MESSAGE, "", post.ChannelId, userId, nil)
-	message.Add("post", post.ToJson())
+	message.Add("post", a.PostWithProxyAddedToImageURLs(post).ToJson())
 
 	a.Go(func() {
 		a.Publish(message)
@@ -419,7 +424,7 @@ func (a *App) PatchPost(postId string, patch *model.PostPatch) (*model.Post, *mo
 
 func (a *App) sendUpdatedPostEvent(post *model.Post) {
 	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POST_EDITED, "", post.ChannelId, "", nil)
-	message.Add("post", post.ToJson())
+	message.Add("post", a.PostWithProxyAddedToImageURLs(post).ToJson())
 
 	a.Go(func() {
 		a.Publish(message)
@@ -562,7 +567,7 @@ func (a *App) DeletePost(postId string) (*model.Post, *model.AppError) {
 		}
 
 		message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POST_DELETED, "", post.ChannelId, "", nil)
-		message.Add("post", post.ToJson())
+		message.Add("post", a.PostWithProxyAddedToImageURLs(post).ToJson())
 
 		a.Go(func() {
 			a.Publish(message)
@@ -823,3 +828,124 @@ func (a *App) DoPostAction(postId string, actionId string, userId string) *model
 
 	return nil
 }
+
+func (a *App) PostListWithProxyAddedToImageURLs(list *model.PostList) *model.PostList {
+	if f := a.ImageProxyAdder(); f != nil {
+		return list.WithRewrittenImageURLs(f)
+	}
+	return list
+}
+
+func (a *App) PostWithProxyAddedToImageURLs(post *model.Post) *model.Post {
+	if f := a.ImageProxyAdder(); f != nil {
+		return post.WithRewrittenImageURLs(f)
+	}
+	return post
+}
+
+func (a *App) PostWithProxyRemovedFromImageURLs(post *model.Post) *model.Post {
+	if f := a.ImageProxyRemover(); f != nil {
+		return post.WithRewrittenImageURLs(f)
+	}
+	return post
+}
+
+func (a *App) PostPatchWithProxyRemovedFromImageURLs(patch *model.PostPatch) *model.PostPatch {
+	if f := a.ImageProxyRemover(); f != nil {
+		return patch.WithRewrittenImageURLs(f)
+	}
+	return patch
+}
+
+func (a *App) imageProxyConfig() (proxyType, proxyURL, options, siteURL string) {
+	cfg := a.Config()
+
+	if cfg.ServiceSettings.ImageProxyURL == nil || cfg.ServiceSettings.ImageProxyType == nil || cfg.ServiceSettings.SiteURL == nil {
+		return
+	}
+
+	proxyURL = *cfg.ServiceSettings.ImageProxyURL
+	proxyType = *cfg.ServiceSettings.ImageProxyType
+	siteURL = *cfg.ServiceSettings.SiteURL
+
+	if proxyURL == "" || proxyType == "" {
+		return "", "", "", ""
+	}
+
+	if proxyURL[len(proxyURL)-1] != '/' {
+		proxyURL += "/"
+	}
+
+	if cfg.ServiceSettings.ImageProxyOptions != nil {
+		options = *cfg.ServiceSettings.ImageProxyOptions
+	}
+
+	return
+}
+
+func (a *App) ImageProxyAdder() func(string) string {
+	proxyType, proxyURL, options, siteURL := a.imageProxyConfig()
+	if proxyType == "" {
+		return nil
+	}
+
+	return func(url string) string {
+		if strings.HasPrefix(url, proxyURL) {
+			return url
+		}
+
+		if url[0] == '/' {
+			url = siteURL + url
+		}
+
+		switch proxyType {
+		case "atmos/camo":
+			mac := hmac.New(sha1.New, []byte(options))
+			mac.Write([]byte(url))
+			digest := hex.EncodeToString(mac.Sum(nil))
+			return proxyURL + digest + "/" + hex.EncodeToString([]byte(url))
+		case "willnorris/imageproxy":
+			options := strings.Split(options, "|")
+			if len(options) > 1 {
+				mac := hmac.New(sha256.New, []byte(options[1]))
+				mac.Write([]byte(url))
+				digest := base64.URLEncoding.EncodeToString(mac.Sum(nil))
+				if options[0] == "" {
+					return proxyURL + "s" + digest + "/" + url
+				}
+				return proxyURL + options[0] + ",s" + digest + "/" + url
+			}
+			return proxyURL + options[0] + "/" + url
+		}
+
+		return url
+	}
+}
+
+func (a *App) ImageProxyRemover() (f func(string) string) {
+	proxyType, proxyURL, _, _ := a.imageProxyConfig()
+	if proxyType == "" {
+		return nil
+	}
+
+	return func(url string) string {
+		switch proxyType {
+		case "atmos/camo":
+			if strings.HasPrefix(url, proxyURL) {
+				if slash := strings.IndexByte(url[len(proxyURL):], '/'); slash >= 0 {
+					if decoded, err := hex.DecodeString(url[len(proxyURL)+slash+1:]); err == nil {
+						return string(decoded)
+					}
+				}
+			}
+		case "willnorris/imageproxy":
+			if strings.HasPrefix(url, proxyURL) {
+				if slash := strings.IndexByte(url[len(proxyURL):], '/'); slash >= 0 {
+					return url[len(proxyURL)+slash+1:]
+				}
+			}
+		}
+
+		return url
+	}
+}
diff --git a/app/post_test.go b/app/post_test.go
index 82eac3cd1..9854bb707 100644
--- a/app/post_test.go
+++ b/app/post_test.go
@@ -185,3 +185,84 @@ func TestPostChannelMentions(t *testing.T) {
 		},
 	}, result.Props["channel_mentions"])
 }
+
+func TestImageProxy(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+
+	for name, tc := range map[string]struct {
+		ProxyType       string
+		ProxyURL        string
+		ProxyOptions    string
+		ImageURL        string
+		ProxiedImageURL string
+	}{
+		"atmos/camo": {
+			ProxyType:       "atmos/camo",
+			ProxyURL:        "https://127.0.0.1",
+			ProxyOptions:    "foo",
+			ImageURL:        "http://mydomain.com/myimage",
+			ProxiedImageURL: "https://127.0.0.1/f8dace906d23689e8d5b12c3cefbedbf7b9b72f5/687474703a2f2f6d79646f6d61696e2e636f6d2f6d79696d616765",
+		},
+		"willnorris/imageproxy": {
+			ProxyType:       "willnorris/imageproxy",
+			ProxyURL:        "https://127.0.0.1",
+			ProxyOptions:    "x1000",
+			ImageURL:        "http://mydomain.com/myimage",
+			ProxiedImageURL: "https://127.0.0.1/x1000/http://mydomain.com/myimage",
+		},
+		"willnorris/imageproxy_WithSigning": {
+			ProxyType:       "willnorris/imageproxy",
+			ProxyURL:        "https://127.0.0.1",
+			ProxyOptions:    "x1000|foo",
+			ImageURL:        "http://mydomain.com/myimage",
+			ProxiedImageURL: "https://127.0.0.1/x1000,sbhHVoG5d60UvnNtGh6Iy6x4PaMmnsh8JfZ7JfErKjGU=/http://mydomain.com/myimage",
+		},
+	} {
+		t.Run(name, func(t *testing.T) {
+			th.App.UpdateConfig(func(cfg *model.Config) {
+				cfg.ServiceSettings.ImageProxyType = model.NewString(tc.ProxyType)
+				cfg.ServiceSettings.ImageProxyOptions = model.NewString(tc.ProxyOptions)
+				cfg.ServiceSettings.ImageProxyURL = model.NewString(tc.ProxyURL)
+			})
+
+			post := &model.Post{
+				Id:      model.NewId(),
+				Message: "![foo](" + tc.ImageURL + ")",
+			}
+
+			list := model.NewPostList()
+			list.Posts[post.Id] = post
+
+			assert.Equal(t, "![foo]("+tc.ProxiedImageURL+")", th.App.PostListWithProxyAddedToImageURLs(list).Posts[post.Id].Message)
+			assert.Equal(t, "![foo]("+tc.ProxiedImageURL+")", th.App.PostWithProxyAddedToImageURLs(post).Message)
+
+			assert.Equal(t, "![foo]("+tc.ImageURL+")", th.App.PostWithProxyRemovedFromImageURLs(post).Message)
+			post.Message = "![foo](" + tc.ProxiedImageURL + ")"
+			assert.Equal(t, "![foo]("+tc.ImageURL+")", th.App.PostWithProxyRemovedFromImageURLs(post).Message)
+		})
+	}
+}
+
+var imageProxyBenchmarkSink *model.Post
+
+func BenchmarkPostWithProxyRemovedFromImageURLs(b *testing.B) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+
+	th.App.UpdateConfig(func(cfg *model.Config) {
+		cfg.ServiceSettings.ImageProxyType = model.NewString("willnorris/imageproxy")
+		cfg.ServiceSettings.ImageProxyOptions = model.NewString("x1000|foo")
+		cfg.ServiceSettings.ImageProxyURL = model.NewString("https://127.0.0.1")
+	})
+
+	post := &model.Post{
+		Message: "![foo](http://mydomain.com/myimage)",
+	}
+
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		imageProxyBenchmarkSink = th.App.PostWithProxyAddedToImageURLs(post)
+	}
+}
diff --git a/app/reaction.go b/app/reaction.go
index bf0d20e2b..062622f34 100644
--- a/app/reaction.go
+++ b/app/reaction.go
@@ -62,6 +62,6 @@ func (a *App) sendReactionEvent(event string, reaction *model.Reaction, post *mo
 	post.HasReactions = true
 	post.UpdateAt = model.GetMillis()
 	umessage := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POST_EDITED, "", post.ChannelId, "", nil)
-	umessage.Add("post", post.ToJson())
+	umessage.Add("post", a.PostWithProxyAddedToImageURLs(post).ToJson())
 	a.Publish(umessage)
 }
diff --git a/config/default.json b/config/default.json
index 6ebf29789..6474043cb 100644
--- a/config/default.json
+++ b/config/default.json
@@ -56,7 +56,9 @@
         "EnablePreviewFeatures": true,
         "CloseUnusedDirectMessages": false,
         "EnableTutorial": true,
-        "ExperimentalEnableDefaultChannelLeaveJoinMessages": true
+        "ExperimentalEnableDefaultChannelLeaveJoinMessages": true,
+        "ImageProxyType": "",
+        "ImageProxyURL": ""
     },
     "TeamSettings": {
         "SiteName": "Mattermost",
diff --git a/i18n/en.json b/i18n/en.json
index cf82f6644..e40d4bc67 100644
--- a/i18n/en.json
+++ b/i18n/en.json
@@ -4815,6 +4815,14 @@
     "translation": "Invalid listen address for service settings Must be set."
   },
   {
+    "id": "model.config.is_valid.image_proxy_type.app_error",
+    "translation": "Invalid image proxy type for service settings."
+  },
+  {
+    "id": "model.config.is_valid.atmos_camo_image_proxy_options.app_error",
+    "translation": "Invalid atmos/camo image proxy options for service settings. Must be set to your shared key."
+  },
+  {
     "id": "model.config.is_valid.localization.available_locales.app_error",
     "translation": "Available Languages must contain Default Client Language"
   },
diff --git a/model/config.go b/model/config.go
index d1bb0a41c..6e3e8859e 100644
--- a/model/config.go
+++ b/model/config.go
@@ -214,6 +214,9 @@ type ServiceSettings struct {
 	EnablePreviewFeatures                             *bool
 	EnableTutorial                                    *bool
 	ExperimentalEnableDefaultChannelLeaveJoinMessages *bool
+	ImageProxyType                                    *string
+	ImageProxyURL                                     *string
+	ImageProxyOptions                                 *string
 }
 
 func (s *ServiceSettings) SetDefaults() {
@@ -250,7 +253,7 @@ func (s *ServiceSettings) SetDefaults() {
 	}
 
 	if s.AllowedUntrustedInternalConnections == nil {
-		s.AllowedUntrustedInternalConnections = new(string)
+		s.AllowedUntrustedInternalConnections = NewString("")
 	}
 
 	if s.EnableMultifactorAuthentication == nil {
@@ -418,6 +421,18 @@ func (s *ServiceSettings) SetDefaults() {
 	if s.ExperimentalEnableDefaultChannelLeaveJoinMessages == nil {
 		s.ExperimentalEnableDefaultChannelLeaveJoinMessages = NewBool(true)
 	}
+
+	if s.ImageProxyType == nil {
+		s.ImageProxyType = NewString("")
+	}
+
+	if s.ImageProxyURL == nil {
+		s.ImageProxyURL = NewString("")
+	}
+
+	if s.ImageProxyOptions == nil {
+		s.ImageProxyOptions = NewString("")
+	}
 }
 
 type ClusterSettings struct {
@@ -2050,6 +2065,16 @@ func (ss *ServiceSettings) isValid() *AppError {
 		return NewAppError("Config.IsValid", "model.config.is_valid.listen_address.app_error", nil, "", http.StatusBadRequest)
 	}
 
+	switch *ss.ImageProxyType {
+	case "", "willnorris/imageproxy":
+	case "atmos/camo":
+		if *ss.ImageProxyOptions == "" {
+			return NewAppError("Config.IsValid", "model.config.is_valid.atmos_camo_image_proxy_options.app_error", nil, "", http.StatusBadRequest)
+		}
+	default:
+		return NewAppError("Config.IsValid", "model.config.is_valid.image_proxy_type.app_error", nil, "", http.StatusBadRequest)
+	}
+
 	return nil
 }
 
diff --git a/model/post.go b/model/post.go
index 2ae8d902d..950bf401c 100644
--- a/model/post.go
+++ b/model/post.go
@@ -8,8 +8,11 @@ import (
 	"io"
 	"net/http"
 	"regexp"
+	"sort"
 	"strings"
 	"unicode/utf8"
+
+	"github.com/mattermost/mattermost-server/utils/markdown"
 )
 
 const (
@@ -43,18 +46,25 @@ const (
 )
 
 type Post struct {
-	Id            string          `json:"id"`
-	CreateAt      int64           `json:"create_at"`
-	UpdateAt      int64           `json:"update_at"`
-	EditAt        int64           `json:"edit_at"`
-	DeleteAt      int64           `json:"delete_at"`
-	IsPinned      bool            `json:"is_pinned"`
-	UserId        string          `json:"user_id"`
-	ChannelId     string          `json:"channel_id"`
-	RootId        string          `json:"root_id"`
-	ParentId      string          `json:"parent_id"`
-	OriginalId    string          `json:"original_id"`
-	Message       string          `json:"message"`
+	Id         string `json:"id"`
+	CreateAt   int64  `json:"create_at"`
+	UpdateAt   int64  `json:"update_at"`
+	EditAt     int64  `json:"edit_at"`
+	DeleteAt   int64  `json:"delete_at"`
+	IsPinned   bool   `json:"is_pinned"`
+	UserId     string `json:"user_id"`
+	ChannelId  string `json:"channel_id"`
+	RootId     string `json:"root_id"`
+	ParentId   string `json:"parent_id"`
+	OriginalId string `json:"original_id"`
+
+	Message string `json:"message"`
+
+	// MessageSource will contain the message as submitted by the user if Message has been modified
+	// by Mattermost for presentation (e.g if an image proxy is being used). It should be used to
+	// populate edit boxes if present.
+	MessageSource string `json:"message_source,omitempty" db:"-"`
+
 	Type          string          `json:"type"`
 	Props         StringInterface `json:"props"`
 	Hashtags      string          `json:"hashtags"`
@@ -72,6 +82,14 @@ type PostPatch struct {
 	HasReactions *bool            `json:"has_reactions"`
 }
 
+func (o *PostPatch) WithRewrittenImageURLs(f func(string) string) *PostPatch {
+	copy := *o
+	if copy.Message != nil {
+		*copy.Message = RewriteImageURLs(*o.Message, f)
+	}
+	return &copy
+}
+
 type PostForIndexing struct {
 	Post
 	TeamId         string `json:"team_id"`
@@ -392,3 +410,87 @@ func (o *Post) GenerateActionIds() {
 		}
 	}
 }
+
+var markdownDestinationEscaper = strings.NewReplacer(
+	`\`, `\\`,
+	`<`, `\<`,
+	`>`, `\>`,
+	`(`, `\(`,
+	`)`, `\)`,
+)
+
+// WithRewrittenImageURLs returns a new shallow copy of the post where the message has been
+// rewritten via RewriteImageURLs.
+func (o *Post) WithRewrittenImageURLs(f func(string) string) *Post {
+	copy := *o
+	copy.Message = RewriteImageURLs(o.Message, f)
+	if copy.MessageSource == "" && copy.Message != o.Message {
+		copy.MessageSource = o.Message
+	}
+	return &copy
+}
+
+// RewriteImageURLs takes a message and returns a copy that has all of the image URLs replaced
+// according to the function f. For each image URL, f will be invoked, and the resulting markdown
+// will contain the URL returned by that invocation instead.
+//
+// Image URLs are destination URLs used in inline images or reference definitions that are used
+// anywhere in the input markdown as an image.
+func RewriteImageURLs(message string, f func(string) string) string {
+	if !strings.Contains(message, "![") {
+		return message
+	}
+
+	var ranges []markdown.Range
+
+	markdown.Inspect(message, func(blockOrInline interface{}) bool {
+		switch v := blockOrInline.(type) {
+		case *markdown.ReferenceImage:
+			ranges = append(ranges, v.ReferenceDefinition.RawDestination)
+		case *markdown.InlineImage:
+			ranges = append(ranges, v.RawDestination)
+		default:
+			return true
+		}
+		return true
+	})
+
+	if ranges == nil {
+		return message
+	}
+
+	sort.Slice(ranges, func(i, j int) bool {
+		return ranges[i].Position < ranges[j].Position
+	})
+
+	copyRanges := make([]markdown.Range, 0, len(ranges))
+	urls := make([]string, 0, len(ranges))
+	resultLength := len(message)
+
+	start := 0
+	for i, r := range ranges {
+		switch {
+		case i == 0:
+		case r.Position != ranges[i-1].Position:
+			start = ranges[i-1].End
+		default:
+			continue
+		}
+		original := message[r.Position:r.End]
+		replacement := markdownDestinationEscaper.Replace(f(markdown.Unescape(original)))
+		resultLength += len(replacement) - len(original)
+		copyRanges = append(copyRanges, markdown.Range{Position: start, End: r.Position})
+		urls = append(urls, replacement)
+	}
+
+	result := make([]byte, resultLength)
+
+	offset := 0
+	for i, r := range copyRanges {
+		offset += copy(result[offset:], message[r.Position:r.End])
+		offset += copy(result[offset:], urls[i])
+	}
+	copy(result[offset:], message[ranges[len(ranges)-1].End:])
+
+	return string(result)
+}
diff --git a/model/post_list.go b/model/post_list.go
index 018f7d14f..09cddfdcf 100644
--- a/model/post_list.go
+++ b/model/post_list.go
@@ -21,6 +21,15 @@ func NewPostList() *PostList {
 	}
 }
 
+func (o *PostList) WithRewrittenImageURLs(f func(string) string) *PostList {
+	copy := *o
+	copy.Posts = make(map[string]*Post)
+	for id, post := range o.Posts {
+		copy.Posts[id] = post.WithRewrittenImageURLs(f)
+	}
+	return &copy
+}
+
 func (o *PostList) StripActionIntegrations() {
 	posts := o.Posts
 	o.Posts = make(map[string]*Post)
diff --git a/model/post_test.go b/model/post_test.go
index 6a908887d..5d5e7c9ec 100644
--- a/model/post_test.go
+++ b/model/post_test.go
@@ -4,6 +4,7 @@
 package model
 
 import (
+	"io/ioutil"
 	"strings"
 	"testing"
 
@@ -173,3 +174,129 @@ func TestPostSanitizeProps(t *testing.T) {
 		t.Fatal("should not be nil")
 	}
 }
+
+var markdownSample, markdownSampleWithRewrittenImageURLs string
+
+func init() {
+	bytes, err := ioutil.ReadFile("testdata/markdown-sample.md")
+	if err != nil {
+		panic(err)
+	}
+	markdownSample = string(bytes)
+
+	bytes, err = ioutil.ReadFile("testdata/markdown-sample-with-rewritten-image-urls.md")
+	if err != nil {
+		panic(err)
+	}
+	markdownSampleWithRewrittenImageURLs = string(bytes)
+}
+
+func TestRewriteImageURLs(t *testing.T) {
+	for name, tc := range map[string]struct {
+		Markdown string
+		Expected string
+	}{
+		"Empty": {
+			Markdown: ``,
+			Expected: ``,
+		},
+		"NoImages": {
+			Markdown: `foo`,
+			Expected: `foo`,
+		},
+		"Link": {
+			Markdown: `[foo](/url)`,
+			Expected: `[foo](/url)`,
+		},
+		"Image": {
+			Markdown: `![foo](/url)`,
+			Expected: `![foo](rewritten:/url)`,
+		},
+		"SpacedURL": {
+			Markdown: `![foo]( /url )`,
+			Expected: `![foo]( rewritten:/url )`,
+		},
+		"Title": {
+			Markdown: `![foo](/url "title")`,
+			Expected: `![foo](rewritten:/url "title")`,
+		},
+		"Parentheses": {
+			Markdown: `![foo](/url(1) "title")`,
+			Expected: `![foo](rewritten:/url\(1\) "title")`,
+		},
+		"AngleBrackets": {
+			Markdown: `![foo](</url\<1\>\\> "title")`,
+			Expected: `![foo](<rewritten:/url\<1\>\\> "title")`,
+		},
+		"MultipleLines": {
+			Markdown: `![foo](
+				</url\<1\>\\>
+				"title"
+			)`,
+			Expected: `![foo](
+				<rewritten:/url\<1\>\\>
+				"title"
+			)`,
+		},
+		"ReferenceLink": {
+			Markdown: `[foo]: </url\<1\>\\> "title"
+		 		[foo]`,
+			Expected: `[foo]: </url\<1\>\\> "title"
+		 		[foo]`,
+		},
+		"ReferenceImage": {
+			Markdown: `[foo]: </url\<1\>\\> "title"
+		 		![foo]`,
+			Expected: `[foo]: <rewritten:/url\<1\>\\> "title"
+		 		![foo]`,
+		},
+		"MultipleReferenceImages": {
+			Markdown: `[foo]: </url1> "title"
+				[bar]: </url2>
+				[baz]: /url3 "title"
+				[qux]: /url4
+				![foo]![qux]`,
+			Expected: `[foo]: <rewritten:/url1> "title"
+				[bar]: </url2>
+				[baz]: /url3 "title"
+				[qux]: rewritten:/url4
+				![foo]![qux]`,
+		},
+		"DuplicateReferences": {
+			Markdown: `[foo]: </url1> "title"
+				[foo]: </url2>
+				[foo]: /url3 "title"
+				[foo]: /url4
+				![foo]![foo]![foo]`,
+			Expected: `[foo]: <rewritten:/url1> "title"
+				[foo]: </url2>
+				[foo]: /url3 "title"
+				[foo]: /url4
+				![foo]![foo]![foo]`,
+		},
+		"TrailingURL": {
+			Markdown: "![foo]\n\n[foo]: /url",
+			Expected: "![foo]\n\n[foo]: rewritten:/url",
+		},
+		"Sample": {
+			Markdown: markdownSample,
+			Expected: markdownSampleWithRewrittenImageURLs,
+		},
+	} {
+		t.Run(name, func(t *testing.T) {
+			assert.Equal(t, tc.Expected, RewriteImageURLs(tc.Markdown, func(url string) string {
+				return "rewritten:" + url
+			}))
+		})
+	}
+}
+
+var rewriteImageURLsSink string
+
+func BenchmarkRewriteImageURLs(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		rewriteImageURLsSink = RewriteImageURLs(markdownSample, func(url string) string {
+			return "rewritten:" + url
+		})
+	}
+}
diff --git a/model/testdata/markdown-sample-with-rewritten-image-urls.md b/model/testdata/markdown-sample-with-rewritten-image-urls.md
new file mode 100644
index 000000000..6683bc459
--- /dev/null
+++ b/model/testdata/markdown-sample-with-rewritten-image-urls.md
@@ -0,0 +1,245 @@
+---
+__Advertisement :)__
+
+- __[pica](https://nodeca.github.io/pica/demo/)__ - high quality and fast image
+  resize in browser.
+- __[babelfish](https://github.com/nodeca/babelfish/)__ - developer friendly
+  i18n with plurals support and easy syntax.
+
+You will like those projects!
+
+---
+
+# h1 Heading 8-)
+## h2 Heading
+### h3 Heading
+#### h4 Heading
+##### h5 Heading
+###### h6 Heading
+
+
+## Horizontal Rules
+
+___
+
+---
+
+***
+
+
+## Typographic replacements
+
+Enable typographer option to see result.
+
+(c) (C) (r) (R) (tm) (TM) (p) (P) +-
+
+test.. test... test..... test?..... test!....
+
+!!!!!! ???? ,,  -- ---
+
+"Smartypants, double quotes" and 'single quotes'
+
+
+## Emphasis
+
+**This is bold text**
+
+__This is bold text__
+
+*This is italic text*
+
+_This is italic text_
+
+~~Strikethrough~~
+
+
+## Blockquotes
+
+
+> Blockquotes can also be nested...
+>> ...by using additional greater-than signs right next to each other...
+> > > ...or with spaces between arrows.
+
+
+## Lists
+
+Unordered
+
++ Create a list by starting a line with `+`, `-`, or `*`
++ Sub-lists are made by indenting 2 spaces:
+  - Marker character change forces new list start:
+    * Ac tristique libero volutpat at
+    + Facilisis in pretium nisl aliquet
+    - Nulla volutpat aliquam velit
++ Very easy!
+
+Ordered
+
+1. Lorem ipsum dolor sit amet
+2. Consectetur adipiscing elit
+3. Integer molestie lorem at massa
+
+
+1. You can use sequential numbers...
+1. ...or keep all the numbers as `1.`
+
+Start numbering with offset:
+
+57. foo
+1. bar
+
+
+## Code
+
+Inline `code`
+
+Indented code
+
+    // Some comments
+    line 1 of code
+    line 2 of code
+    line 3 of code
+
+
+Block code "fences"
+
+```
+Sample text here...
+```
+
+Syntax highlighting
+
+``` js
+var foo = function (bar) {
+  return bar++;
+};
+
+console.log(foo(5));
+```
+
+## Tables
+
+| Option | Description |
+| ------ | ----------- |
+| data   | path to data files to supply the data that will be passed into templates. |
+| engine | engine to be used for processing templates. Handlebars is the default. |
+| ext    | extension to be used for dest files. |
+
+Right aligned columns
+
+| Option | Description |
+| ------:| -----------:|
+| data   | path to data files to supply the data that will be passed into templates. |
+| engine | engine to be used for processing templates. Handlebars is the default. |
+| ext    | extension to be used for dest files. |
+
+
+## Links
+
+[link text](http://dev.nodeca.com)
+
+[link with title](http://nodeca.github.io/pica/demo/ "title text!")
+
+Autoconverted link https://github.com/nodeca/pica (enable linkify to see)
+
+
+## Images
+
+![Minion](rewritten:https://octodex.github.com/images/minion.png)
+![Stormtroopocat](rewritten:https://octodex.github.com/images/stormtroopocat.jpg "The Stormtroopocat")
+
+Like links, Images also have a footnote style syntax
+
+![Alt text][id]
+
+With a reference later in the document defining the URL location:
+
+[id]: rewritten:https://octodex.github.com/images/dojocat.jpg  "The Dojocat"
+
+
+## Plugins
+
+The killer feature of `markdown-it` is very effective support of
+[syntax plugins](https://www.npmjs.org/browse/keyword/markdown-it-plugin).
+
+
+### [Emojies](https://github.com/markdown-it/markdown-it-emoji)
+
+> Classic markup: :wink: :crush: :cry: :tear: :laughing: :yum:
+>
+> Shortcuts (emoticons): :-) :-( 8-) ;)
+
+see [how to change output](https://github.com/markdown-it/markdown-it-emoji#change-output) with twemoji.
+
+
+### [Subscript](https://github.com/markdown-it/markdown-it-sub) / [Superscript](https://github.com/markdown-it/markdown-it-sup)
+
+- 19^th^
+- H~2~O
+
+
+### [\<ins>](https://github.com/markdown-it/markdown-it-ins)
+
+++Inserted text++
+
+
+### [\<mark>](https://github.com/markdown-it/markdown-it-mark)
+
+==Marked text==
+
+
+### [Footnotes](https://github.com/markdown-it/markdown-it-footnote)
+
+Footnote 1 link[^first].
+
+Footnote 2 link[^second].
+
+Inline footnote^[Text of inline footnote] definition.
+
+Duplicated footnote reference[^second].
+
+[^first]: Footnote **can have markup**
+
+    and multiple paragraphs.
+
+[^second]: Footnote text.
+
+
+### [Definition lists](https://github.com/markdown-it/markdown-it-deflist)
+
+Term 1
+
+:   Definition 1
+with lazy continuation.
+
+Term 2 with *inline markup*
+
+:   Definition 2
+
+        { some code, part of Definition 2 }
+
+    Third paragraph of definition 2.
+
+_Compact style:_
+
+Term 1
+  ~ Definition 1
+
+Term 2
+  ~ Definition 2a
+  ~ Definition 2b
+
+
+### [Abbreviations](https://github.com/markdown-it/markdown-it-abbr)
+
+This is HTML abbreviation example.
+
+It converts "HTML", but keep intact partial entries like "xxxHTMLyyy" and so on.
+
+*[HTML]: Hyper Text Markup Language
+
+### [Custom containers](https://github.com/markdown-it/markdown-it-container)
+
+::: warning
+*here be dragons*
+:::
diff --git a/model/testdata/markdown-sample.md b/model/testdata/markdown-sample.md
new file mode 100644
index 000000000..f894c1d35
--- /dev/null
+++ b/model/testdata/markdown-sample.md
@@ -0,0 +1,245 @@
+---
+__Advertisement :)__
+
+- __[pica](https://nodeca.github.io/pica/demo/)__ - high quality and fast image
+  resize in browser.
+- __[babelfish](https://github.com/nodeca/babelfish/)__ - developer friendly
+  i18n with plurals support and easy syntax.
+
+You will like those projects!
+
+---
+
+# h1 Heading 8-)
+## h2 Heading
+### h3 Heading
+#### h4 Heading
+##### h5 Heading
+###### h6 Heading
+
+
+## Horizontal Rules
+
+___
+
+---
+
+***
+
+
+## Typographic replacements
+
+Enable typographer option to see result.
+
+(c) (C) (r) (R) (tm) (TM) (p) (P) +-
+
+test.. test... test..... test?..... test!....
+
+!!!!!! ???? ,,  -- ---
+
+"Smartypants, double quotes" and 'single quotes'
+
+
+## Emphasis
+
+**This is bold text**
+
+__This is bold text__
+
+*This is italic text*
+
+_This is italic text_
+
+~~Strikethrough~~
+
+
+## Blockquotes
+
+
+> Blockquotes can also be nested...
+>> ...by using additional greater-than signs right next to each other...
+> > > ...or with spaces between arrows.
+
+
+## Lists
+
+Unordered
+
++ Create a list by starting a line with `+`, `-`, or `*`
++ Sub-lists are made by indenting 2 spaces:
+  - Marker character change forces new list start:
+    * Ac tristique libero volutpat at
+    + Facilisis in pretium nisl aliquet
+    - Nulla volutpat aliquam velit
++ Very easy!
+
+Ordered
+
+1. Lorem ipsum dolor sit amet
+2. Consectetur adipiscing elit
+3. Integer molestie lorem at massa
+
+
+1. You can use sequential numbers...
+1. ...or keep all the numbers as `1.`
+
+Start numbering with offset:
+
+57. foo
+1. bar
+
+
+## Code
+
+Inline `code`
+
+Indented code
+
+    // Some comments
+    line 1 of code
+    line 2 of code
+    line 3 of code
+
+
+Block code "fences"
+
+```
+Sample text here...
+```
+
+Syntax highlighting
+
+``` js
+var foo = function (bar) {
+  return bar++;
+};
+
+console.log(foo(5));
+```
+
+## Tables
+
+| Option | Description |
+| ------ | ----------- |
+| data   | path to data files to supply the data that will be passed into templates. |
+| engine | engine to be used for processing templates. Handlebars is the default. |
+| ext    | extension to be used for dest files. |
+
+Right aligned columns
+
+| Option | Description |
+| ------:| -----------:|
+| data   | path to data files to supply the data that will be passed into templates. |
+| engine | engine to be used for processing templates. Handlebars is the default. |
+| ext    | extension to be used for dest files. |
+
+
+## Links
+
+[link text](http://dev.nodeca.com)
+
+[link with title](http://nodeca.github.io/pica/demo/ "title text!")
+
+Autoconverted link https://github.com/nodeca/pica (enable linkify to see)
+
+
+## Images
+
+![Minion](https://octodex.github.com/images/minion.png)
+![Stormtroopocat](https://octodex.github.com/images/stormtroopocat.jpg "The Stormtroopocat")
+
+Like links, Images also have a footnote style syntax
+
+![Alt text][id]
+
+With a reference later in the document defining the URL location:
+
+[id]: https://octodex.github.com/images/dojocat.jpg  "The Dojocat"
+
+
+## Plugins
+
+The killer feature of `markdown-it` is very effective support of
+[syntax plugins](https://www.npmjs.org/browse/keyword/markdown-it-plugin).
+
+
+### [Emojies](https://github.com/markdown-it/markdown-it-emoji)
+
+> Classic markup: :wink: :crush: :cry: :tear: :laughing: :yum:
+>
+> Shortcuts (emoticons): :-) :-( 8-) ;)
+
+see [how to change output](https://github.com/markdown-it/markdown-it-emoji#change-output) with twemoji.
+
+
+### [Subscript](https://github.com/markdown-it/markdown-it-sub) / [Superscript](https://github.com/markdown-it/markdown-it-sup)
+
+- 19^th^
+- H~2~O
+
+
+### [\<ins>](https://github.com/markdown-it/markdown-it-ins)
+
+++Inserted text++
+
+
+### [\<mark>](https://github.com/markdown-it/markdown-it-mark)
+
+==Marked text==
+
+
+### [Footnotes](https://github.com/markdown-it/markdown-it-footnote)
+
+Footnote 1 link[^first].
+
+Footnote 2 link[^second].
+
+Inline footnote^[Text of inline footnote] definition.
+
+Duplicated footnote reference[^second].
+
+[^first]: Footnote **can have markup**
+
+    and multiple paragraphs.
+
+[^second]: Footnote text.
+
+
+### [Definition lists](https://github.com/markdown-it/markdown-it-deflist)
+
+Term 1
+
+:   Definition 1
+with lazy continuation.
+
+Term 2 with *inline markup*
+
+:   Definition 2
+
+        { some code, part of Definition 2 }
+
+    Third paragraph of definition 2.
+
+_Compact style:_
+
+Term 1
+  ~ Definition 1
+
+Term 2
+  ~ Definition 2a
+  ~ Definition 2b
+
+
+### [Abbreviations](https://github.com/markdown-it/markdown-it-abbr)
+
+This is HTML abbreviation example.
+
+It converts "HTML", but keep intact partial entries like "xxxHTMLyyy" and so on.
+
+*[HTML]: Hyper Text Markup Language
+
+### [Custom containers](https://github.com/markdown-it/markdown-it-container)
+
+::: warning
+*here be dragons*
+:::
diff --git a/utils/markdown/block_quote.go b/utils/markdown/block_quote.go
new file mode 100644
index 000000000..04a324617
--- /dev/null
+++ b/utils/markdown/block_quote.go
@@ -0,0 +1,62 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+type BlockQuote struct {
+	blockBase
+	markdown string
+
+	Children []Block
+}
+
+func (b *BlockQuote) Continuation(indentation int, r Range) *continuation {
+	if indentation > 3 {
+		return nil
+	}
+	s := b.markdown[r.Position:r.End]
+	if s == "" || s[0] != '>' {
+		return nil
+	}
+	remaining := Range{r.Position + 1, r.End}
+	indentation, indentationBytes := countIndentation(b.markdown, remaining)
+	if indentation > 0 {
+		indentation--
+	}
+	return &continuation{
+		Indentation: indentation,
+		Remaining:   Range{remaining.Position + indentationBytes, remaining.End},
+	}
+}
+
+func (b *BlockQuote) AddChild(openBlocks []Block) []Block {
+	b.Children = append(b.Children, openBlocks[0])
+	return openBlocks
+}
+
+func blockQuoteStart(markdown string, indent int, r Range, matchedBlocks, unmatchedBlocks []Block) []Block {
+	if indent > 3 {
+		return nil
+	}
+	s := markdown[r.Position:r.End]
+	if s == "" || s[0] != '>' {
+		return nil
+	}
+
+	block := &BlockQuote{
+		markdown: markdown,
+	}
+	r.Position++
+	if len(s) > 1 && s[1] == ' ' {
+		r.Position++
+	}
+
+	indent, bytes := countIndentation(markdown, r)
+
+	ret := []Block{block}
+	if descendants := blockStartOrParagraph(markdown, indent, Range{r.Position + bytes, r.End}, nil, nil); descendants != nil {
+		block.Children = append(block.Children, descendants[0])
+		ret = append(ret, descendants...)
+	}
+	return ret
+}
diff --git a/utils/markdown/blocks.go b/utils/markdown/blocks.go
new file mode 100644
index 000000000..14972f943
--- /dev/null
+++ b/utils/markdown/blocks.go
@@ -0,0 +1,153 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type continuation struct {
+	Indentation int
+	Remaining   Range
+}
+
+type Block interface {
+	Continuation(indentation int, r Range) *continuation
+	AddLine(indentation int, r Range) bool
+	Close()
+	AllowsBlockStarts() bool
+	HasTrailingBlankLine() bool
+}
+
+type blockBase struct{}
+
+func (*blockBase) AddLine(indentation int, r Range) bool { return false }
+func (*blockBase) Close()                                {}
+func (*blockBase) AllowsBlockStarts() bool               { return true }
+func (*blockBase) HasTrailingBlankLine() bool            { return false }
+
+type ContainerBlock interface {
+	Block
+	AddChild(openBlocks []Block) []Block
+}
+
+type Range struct {
+	Position int
+	End      int
+}
+
+func closeBlocks(blocks []Block, referenceDefinitions *[]*ReferenceDefinition) {
+	for _, block := range blocks {
+		block.Close()
+		if p, ok := block.(*Paragraph); ok && len(p.ReferenceDefinitions) > 0 {
+			*referenceDefinitions = append(*referenceDefinitions, p.ReferenceDefinitions...)
+		}
+	}
+}
+
+func ParseBlocks(markdown string, lines []Line) (*Document, []*ReferenceDefinition) {
+	document := &Document{}
+	var referenceDefinitions []*ReferenceDefinition
+
+	openBlocks := []Block{document}
+
+	for _, line := range lines {
+		r := line.Range
+		lastMatchIndex := 0
+
+		indentation, indentationBytes := countIndentation(markdown, r)
+		r = Range{r.Position + indentationBytes, r.End}
+
+		for i, block := range openBlocks {
+			if continuation := block.Continuation(indentation, r); continuation != nil {
+				indentation = continuation.Indentation
+				r = continuation.Remaining
+				additionalIndentation, additionalIndentationBytes := countIndentation(markdown, r)
+				r = Range{r.Position + additionalIndentationBytes, r.End}
+				indentation += additionalIndentation
+				lastMatchIndex = i
+			} else {
+				break
+			}
+		}
+
+		if openBlocks[lastMatchIndex].AllowsBlockStarts() {
+			if newBlocks := blockStart(markdown, indentation, r, openBlocks[:lastMatchIndex+1], openBlocks[lastMatchIndex+1:]); newBlocks != nil {
+				didAdd := false
+				for i := lastMatchIndex; i >= 0; i-- {
+					if container, ok := openBlocks[i].(ContainerBlock); ok {
+						if newBlocks := container.AddChild(newBlocks); newBlocks != nil {
+							closeBlocks(openBlocks[i+1:], &referenceDefinitions)
+							openBlocks = openBlocks[:i+1]
+							openBlocks = append(openBlocks, newBlocks...)
+							didAdd = true
+							break
+						}
+					}
+				}
+				if didAdd {
+					continue
+				}
+			}
+		}
+
+		isBlank := strings.TrimSpace(markdown[r.Position:r.End]) == ""
+		if paragraph, ok := openBlocks[len(openBlocks)-1].(*Paragraph); ok && !isBlank {
+			paragraph.Text = append(paragraph.Text, r)
+			continue
+		}
+
+		closeBlocks(openBlocks[lastMatchIndex+1:], &referenceDefinitions)
+		openBlocks = openBlocks[:lastMatchIndex+1]
+
+		if openBlocks[lastMatchIndex].AddLine(indentation, r) {
+			continue
+		}
+
+		if paragraph := newParagraph(markdown, r); paragraph != nil {
+			for i := lastMatchIndex; i >= 0; i-- {
+				if container, ok := openBlocks[i].(ContainerBlock); ok {
+					if newBlocks := container.AddChild([]Block{paragraph}); newBlocks != nil {
+						closeBlocks(openBlocks[i+1:], &referenceDefinitions)
+						openBlocks = openBlocks[:i+1]
+						openBlocks = append(openBlocks, newBlocks...)
+						break
+					}
+				}
+			}
+		}
+	}
+
+	closeBlocks(openBlocks, &referenceDefinitions)
+
+	return document, referenceDefinitions
+}
+
+func blockStart(markdown string, indentation int, r Range, matchedBlocks, unmatchedBlocks []Block) []Block {
+	if r.Position >= r.End {
+		return nil
+	}
+
+	if start := blockQuoteStart(markdown, indentation, r, matchedBlocks, unmatchedBlocks); start != nil {
+		return start
+	} else if start := listStart(markdown, indentation, r, matchedBlocks, unmatchedBlocks); start != nil {
+		return start
+	} else if start := indentedCodeStart(markdown, indentation, r, matchedBlocks, unmatchedBlocks); start != nil {
+		return start
+	} else if start := fencedCodeStart(markdown, indentation, r, matchedBlocks, unmatchedBlocks); start != nil {
+		return start
+	}
+
+	return nil
+}
+
+func blockStartOrParagraph(markdown string, indentation int, r Range, matchedBlocks, unmatchedBlocks []Block) []Block {
+	if start := blockStart(markdown, indentation, r, matchedBlocks, unmatchedBlocks); start != nil {
+		return start
+	}
+	if paragraph := newParagraph(markdown, r); paragraph != nil {
+		return []Block{paragraph}
+	}
+	return nil
+}
diff --git a/utils/markdown/commonmark_test.go b/utils/markdown/commonmark_test.go
new file mode 100644
index 000000000..0a0959030
--- /dev/null
+++ b/utils/markdown/commonmark_test.go
@@ -0,0 +1,1001 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCommonMarkReferenceStrings(t *testing.T) {
+	// For the most part, we aim for CommonMark compliance with the features that we support. We
+	// also support some GitHub flavored extensions.
+	//
+	// You can find most of the references used here: https://github.github.com/gfm/
+
+	// CommonMark handles leading tabs that aren't on 4-character boundaries differently, so the
+	// following reference strings will fail. The current implementation is much closer to our
+	// webapp's behavior though, so I'm leaving it as is for now. It doesn't really impact anything
+	// we use this package for anyways.
+	//
+	// "  \tfoo\tbaz\t\tbim\n": "<pre><code>foo\tbaz\t\tbim\n</code></pre>",
+	// ">\t\tfoo":              "<blockquote><pre><code>   foo</code></pre></blockquote>",
+
+	for name, tc := range map[string]struct {
+		Markdown     string
+		ExpectedHTML string
+	}{
+		"0.28-gfm-1": {
+			Markdown:     "\tfoo\tbaz\t\tbim\n",
+			ExpectedHTML: "<pre><code>foo\tbaz\t\tbim\n</code></pre>",
+		},
+		"0.28-gfm-3": {
+			Markdown:     "    a\ta\n    ὐ\ta\n",
+			ExpectedHTML: "<pre><code>a\ta\nὐ\ta\n</code></pre>",
+		},
+		"0.28-gfm-4": {
+			Markdown:     "  - foo\n\n\tbar\n",
+			ExpectedHTML: "<ul><li><p>foo</p><p>bar</p></li></ul>",
+		},
+		"0.28-gfm-5": {
+			Markdown:     "- foo\n\n\t\tbar",
+			ExpectedHTML: "<ul><li><p>foo</p><pre><code>  bar</code></pre></li></ul>",
+		},
+		"0.28-gfm-8": {
+			Markdown:     "    foo\n\tbar",
+			ExpectedHTML: "<pre><code>foo\nbar</code></pre>",
+		},
+		"0.28-gfm-9": {
+			Markdown:     " - foo\n   - bar\n\t - baz",
+			ExpectedHTML: "<ul><li>foo<ul><li>bar<ul><li>baz</li></ul></li></ul></li></ul>",
+		},
+		"0.28-gfm-12": {
+			Markdown:     "- `one\n- two`",
+			ExpectedHTML: "<ul><li>`one</li><li>two`</li></ul>",
+		},
+		"0.28-gfm-76": {
+			Markdown:     "    a simple\n      indented code block",
+			ExpectedHTML: "<pre><code>a simple\n  indented code block</code></pre>",
+		},
+		"0.28-gfm-77": {
+			Markdown:     "  - foo\n\n    bar",
+			ExpectedHTML: "<ul><li><p>foo</p><p>bar</p></li></ul>",
+		},
+		"0.28-gfm-78": {
+			Markdown:     "1.  foo\n\n    - bar",
+			ExpectedHTML: "<ol><li><p>foo</p><ul><li>bar</li></ul></li></ol>",
+		},
+		"0.28-gfm-79": {
+			Markdown:     "    <a/>\n    *hi*\n\n    - one",
+			ExpectedHTML: "<pre><code>&lt;a/&gt;\n*hi*\n\n- one</code></pre>",
+		},
+		"0.28-gfm-80": {
+			Markdown:     "    chunk1\n\n    chunk2\n  \n \n \n    chunk3",
+			ExpectedHTML: "<pre><code>chunk1\n\nchunk2\n\n\n\nchunk3</code></pre>",
+		},
+		"0.28-gfm-81": {
+			Markdown:     "    chunk1\n      \n      chunk2",
+			ExpectedHTML: "<pre><code>chunk1\n  \n  chunk2</code></pre>",
+		},
+		"0.28-gfm-82": {
+			Markdown:     "Foo\n    bar",
+			ExpectedHTML: "<p>Foo\nbar</p>",
+		},
+		"0.28-gfm-83": {
+			Markdown:     "    foo\nbar",
+			ExpectedHTML: "<pre><code>foo\n</code></pre><p>bar</p>",
+		},
+		"0.28-gfm-85": {
+			Markdown:     "        foo\n    bar",
+			ExpectedHTML: "<pre><code>    foo\nbar</code></pre>",
+		},
+		"0.28-gfm-86": {
+			Markdown:     "\n    \n    foo\n    ",
+			ExpectedHTML: "<pre><code>foo\n</code></pre>",
+		},
+		"0.28-gfm-87": {
+			Markdown:     "    foo  ",
+			ExpectedHTML: "<pre><code>foo  </code></pre>",
+		},
+		"0.28-gfm-88": {
+			Markdown:     "```\n<\n >\n```",
+			ExpectedHTML: "<pre><code>&lt;\n &gt;\n</code></pre>",
+		},
+		"0.28-gfm-89": {
+			Markdown:     "~~~\n<\n >\n~~~",
+			ExpectedHTML: "<pre><code>&lt;\n &gt;\n</code></pre>",
+		},
+		"0.28-gfm-91": {
+			Markdown:     "```\naaa\n~~~\n```",
+			ExpectedHTML: "<pre><code>aaa\n~~~\n</code></pre>",
+		},
+		"0.28-gfm-92": {
+			Markdown:     "~~~\naaa\n```\n~~~",
+			ExpectedHTML: "<pre><code>aaa\n```\n</code></pre>",
+		},
+		"0.28-gfm-93": {
+			Markdown:     "````\naaa\n```\n``````",
+			ExpectedHTML: "<pre><code>aaa\n```\n</code></pre>",
+		},
+		"0.28-gfm-94": {
+			Markdown:     "~~~~\naaa\n~~~\n~~~~",
+			ExpectedHTML: "<pre><code>aaa\n~~~\n</code></pre>",
+		},
+		"0.28-gfm-95": {
+			Markdown:     "```",
+			ExpectedHTML: "<pre><code></code></pre>",
+		},
+		"0.28-gfm-96": {
+			Markdown:     "`````\n\n```\naaa",
+			ExpectedHTML: "<pre><code>\n```\naaa</code></pre>",
+		},
+		"0.28-gfm-97": {
+			Markdown:     "> ```\n> aaa\n\nbbb",
+			ExpectedHTML: "<blockquote><pre><code>aaa\n</code></pre></blockquote><p>bbb</p>",
+		},
+		"0.28-gfm-98": {
+			Markdown:     "```\n\n  \n```",
+			ExpectedHTML: "<pre><code>\n  \n</code></pre>",
+		},
+		"0.28-gfm-99": {
+			Markdown:     "```\n```",
+			ExpectedHTML: "<pre><code></code></pre>",
+		},
+		"0.28-gfm-100": {
+			Markdown:     " ```\n aaa\naaa\n```",
+			ExpectedHTML: "<pre><code>aaa\naaa\n</code></pre>",
+		},
+		"0.28-gfm-101": {
+			Markdown:     "  ```\naaa\n  aaa\naaa\n  ```",
+			ExpectedHTML: "<pre><code>aaa\naaa\naaa\n</code></pre>",
+		},
+		"0.28-gfm-102": {
+			Markdown:     "   ```\n   aaa\n    aaa\n  aaa\n   ```",
+			ExpectedHTML: "<pre><code>aaa\n aaa\naaa\n</code></pre>",
+		},
+		"0.28-gfm-103": {
+			Markdown:     "    ```\n    aaa\n    ```",
+			ExpectedHTML: "<pre><code>```\naaa\n```</code></pre>",
+		},
+		"0.28-gfm-104": {
+			Markdown:     "```\naaa\n  ```",
+			ExpectedHTML: "<pre><code>aaa\n</code></pre>",
+		},
+		"0.28-gfm-105": {
+			Markdown:     "   ```\naaa\n  ```",
+			ExpectedHTML: "<pre><code>aaa\n</code></pre>",
+		},
+		"0.28-gfm-106": {
+			Markdown:     "```\naaa\n    ```",
+			ExpectedHTML: "<pre><code>aaa\n    ```</code></pre>",
+		},
+		"0.28-gfm-108": {
+			Markdown:     "~~~~~~\naaa\n~~~ ~~",
+			ExpectedHTML: "<pre><code>aaa\n~~~ ~~</code></pre>",
+		},
+		"0.28-gfm-109": {
+			Markdown:     "foo\n```\nbar\n```\nbaz",
+			ExpectedHTML: "<p>foo</p><pre><code>bar\n</code></pre><p>baz</p>",
+		},
+		"0.28-gfm-111": {
+			Markdown:     "```ruby\ndef foo(x)\n  return 3\nend\n```",
+			ExpectedHTML: "<pre><code class=\"language-ruby\">def foo(x)\n  return 3\nend\n</code></pre>",
+		},
+		"0.28-gfm-112": {
+			Markdown:     "```ruby startline=3 $%@#$\ndef foo(x)\n  return 3\nend\n```",
+			ExpectedHTML: "<pre><code class=\"language-ruby\">def foo(x)\n  return 3\nend\n</code></pre>",
+		},
+		"0.28-gfm-113": {
+			Markdown:     "````;\n````",
+			ExpectedHTML: "<pre><code class=\"language-;\"></code></pre>",
+		},
+		"0.28-gfm-115": {
+			Markdown:     "```\n``` aaa\n```",
+			ExpectedHTML: "<pre><code>``` aaa\n</code></pre>",
+		},
+		"0.28-gfm-159": {
+			Markdown:     "[foo]: /url \"title\"\n\n[foo]",
+			ExpectedHTML: `<p><a href="/url" title="title">foo</a></p>`,
+		},
+		"0.28-gfm-160": {
+			Markdown:     "   [foo]: \n      /url  \n           'the title'  \n\n[foo]",
+			ExpectedHTML: `<p><a href="/url" title="the title">foo</a></p>`,
+		},
+		"0.28-gfm-161": {
+			Markdown:     "[Foo*bar\\]]:my_(url) 'title (with parens)'\n\n[Foo*bar\\]]",
+			ExpectedHTML: `<p><a href="my_(url)" title="title (with parens)">Foo*bar]</a></p>`,
+		},
+		"0.28-gfm-162": {
+			Markdown:     "[Foo bar]:\n<my%20url>\n'title'\n\n[Foo bar]",
+			ExpectedHTML: `<p><a href="my%20url" title="title">Foo bar</a></p>`,
+		},
+		"0.28-gfm-163": {
+			Markdown:     "[foo]: /url '\ntitle\nline1\nline2\n'\n\n[foo]",
+			ExpectedHTML: "<p><a href=\"/url\" title=\"\ntitle\nline1\nline2\n\">foo</a></p>",
+		},
+		"0.28-gfm-164": {
+			Markdown:     "[foo]: /url 'title\n\nwith blank line'\n\n[foo]",
+			ExpectedHTML: "<p>[foo]: /url 'title</p><p>with blank line'</p><p>[foo]</p>",
+		},
+		"0.28-gfm-165": {
+			Markdown:     "[foo]:\n/url\n\n[foo]",
+			ExpectedHTML: `<p><a href="/url">foo</a></p>`,
+		},
+		"0.28-gfm-166": {
+			Markdown:     "[foo]:\n\n[foo]",
+			ExpectedHTML: `<p>[foo]:</p><p>[foo]</p>`,
+		},
+		"0.28-gfm-167": {
+			Markdown:     "[foo]: /url\\bar\\*baz \"foo\\\"bar\\baz\"\n\n[foo]",
+			ExpectedHTML: `<p><a href="/url%5Cbar*baz" title="foo&quot;bar\baz">foo</a></p>`,
+		},
+		"0.28-gfm-168": {
+			Markdown:     "[foo]\n\n[foo]: url",
+			ExpectedHTML: `<p><a href="url">foo</a></p>`,
+		},
+		"0.28-gfm-169": {
+			Markdown:     "[foo]\n\n[foo]: first\n[foo]: second",
+			ExpectedHTML: `<p><a href="first">foo</a></p>`,
+		},
+		"0.28-gfm-170": {
+			Markdown:     "[FOO]: /url\n\n[Foo]",
+			ExpectedHTML: `<p><a href="/url">Foo</a></p>`,
+		},
+		"0.28-gfm-171": {
+			Markdown:     "[ΑΓΩ]: /φου\n\n[αγω]",
+			ExpectedHTML: `<p><a href="/%CF%86%CE%BF%CF%85">αγω</a></p>`,
+		},
+		"0.28-gfm-172": {
+			Markdown:     "[foo]: /url",
+			ExpectedHTML: ``,
+		},
+		"0.28-gfm-173": {
+			Markdown:     "[\nfoo\n]: /url\nbar",
+			ExpectedHTML: `<p>bar</p>`,
+		},
+		"0.28-gfm-174": {
+			Markdown:     `[foo]: /url "title" ok`,
+			ExpectedHTML: `<p>[foo]: /url &quot;title&quot; ok</p>`,
+		},
+		"0.28-gfm-175": {
+			Markdown:     "[foo]: /url\n\"title\" ok",
+			ExpectedHTML: `<p>&quot;title&quot; ok</p>`,
+		},
+		"0.28-gfm-176": {
+			Markdown:     "    [foo]: /url \"title\"\n\n[foo]",
+			ExpectedHTML: "<pre><code>[foo]: /url &quot;title&quot;\n</code></pre><p>[foo]</p>",
+		},
+		"0.28-gfm-177": {
+			Markdown:     "```\n[foo]: /url\n```\n\n[foo]",
+			ExpectedHTML: "<pre><code>[foo]: /url\n</code></pre><p>[foo]</p>",
+		},
+		"0.28-gfm-178": {
+			Markdown:     "Foo\n[bar]: /baz\n\n[bar]",
+			ExpectedHTML: "<p>Foo\n[bar]: /baz</p><p>[bar]</p>",
+		},
+		"0.28-gfm-180": {
+			Markdown: "[foo]: /foo-url \"foo\"\n[bar]: /bar-url\n\"bar\"\n[baz]: /baz-url\n\n[foo],\n[bar],\n[baz]",
+			ExpectedHTML: `<p><a href="/foo-url" title="foo">foo</a>,
+<a href="/bar-url" title="bar">bar</a>,
+<a href="/baz-url">baz</a></p>`,
+		},
+		"0.28-gfm-181": {
+			Markdown:     "[foo]\n\n> [foo]: /url",
+			ExpectedHTML: `<p><a href="/url">foo</a></p><blockquote></blockquote>`,
+		},
+		"0.28-gfm-182": {
+			Markdown:     "aaa\n\nbbb",
+			ExpectedHTML: "<p>aaa</p><p>bbb</p>",
+		},
+		"0.28-gfm-183": {
+			Markdown:     "aaa\nbbb\n\nccc\nddd",
+			ExpectedHTML: "<p>aaa\nbbb</p><p>ccc\nddd</p>",
+		},
+		"0.28-gfm-184": {
+			Markdown:     "aaa\n\n\nbbb",
+			ExpectedHTML: "<p>aaa</p><p>bbb</p>",
+		},
+		"0.28-gfm-185": {
+			Markdown:     "  aaa\n bbb",
+			ExpectedHTML: "<p>aaa\nbbb</p>",
+		},
+		"0.28-gfm-186": {
+			Markdown:     "aaa\n             bbb\n                                       ccc",
+			ExpectedHTML: "<p>aaa\nbbb\nccc</p>",
+		},
+		"0.28-gfm-187": {
+			Markdown:     "   aaa\nbbb",
+			ExpectedHTML: "<p>aaa\nbbb</p>",
+		},
+		"0.28-gfm-188": {
+			Markdown:     "    aaa\nbbb",
+			ExpectedHTML: "<pre><code>aaa\n</code></pre><p>bbb</p>",
+		},
+		"0.28-gfm-189": {
+			Markdown:     "aaa     \nbbb     \n",
+			ExpectedHTML: "<p>aaa<br />bbb</p>",
+		},
+		"0.28-gfm-204": {
+			Markdown:     "> bar\nbaz\n> foo",
+			ExpectedHTML: "<blockquote><p>bar\nbaz\nfoo</p></blockquote>",
+		},
+		"0.28-gfm-206": {
+			Markdown:     "> - foo\n- bar",
+			ExpectedHTML: "<blockquote><ul><li>foo</li></ul></blockquote><ul><li>bar</li></ul>",
+		},
+		"0.28-gfm-207": {
+			Markdown:     ">     foo\n    bar",
+			ExpectedHTML: "<blockquote><pre><code>foo\n</code></pre></blockquote><pre><code>bar</code></pre>",
+		},
+		"0.28-gfm-208": {
+			Markdown:     "> ```\nfoo\n```",
+			ExpectedHTML: "<blockquote><pre><code></code></pre></blockquote><p>foo</p><pre><code></code></pre>",
+		},
+		"0.28-gfm-209": {
+			Markdown:     "> foo\n    - bar",
+			ExpectedHTML: "<blockquote><p>foo\n- bar</p></blockquote>",
+		},
+		"0.28-gfm-210": {
+			Markdown:     ">",
+			ExpectedHTML: "<blockquote></blockquote>",
+		},
+		"0.28-gfm-211": {
+			Markdown:     ">\n>  \n> ",
+			ExpectedHTML: "<blockquote></blockquote>",
+		},
+		"0.28-gfm-212": {
+			Markdown:     ">\n> foo\n>  ",
+			ExpectedHTML: "<blockquote><p>foo</p></blockquote>",
+		},
+		"0.28-gfm-213": {
+			Markdown:     "> foo\n\n> bar",
+			ExpectedHTML: "<blockquote><p>foo</p></blockquote><blockquote><p>bar</p></blockquote>",
+		},
+		"0.28-gfm-214": {
+			Markdown:     "> foo\n> bar",
+			ExpectedHTML: "<blockquote><p>foo\nbar</p></blockquote>",
+		},
+		"0.28-gfm-215": {
+			Markdown:     "> foo\n>\n> bar",
+			ExpectedHTML: "<blockquote><p>foo</p><p>bar</p></blockquote>",
+		},
+		"0.28-gfm-216": {
+			Markdown:     "foo\n> bar",
+			ExpectedHTML: "<p>foo</p><blockquote><p>bar</p></blockquote>",
+		},
+		"0.28-gfm-218": {
+			Markdown:     "> bar\nbaz",
+			ExpectedHTML: "<blockquote><p>bar\nbaz</p></blockquote>",
+		},
+		"0.28-gfm-219": {
+			Markdown:     "> bar\n\nbaz",
+			ExpectedHTML: "<blockquote><p>bar</p></blockquote><p>baz</p>",
+		},
+		"0.28-gfm-220": {
+			Markdown:     "> bar\n>\nbaz",
+			ExpectedHTML: "<blockquote><p>bar</p></blockquote><p>baz</p>",
+		},
+		"0.28-gfm-221": {
+			Markdown:     "> > > foo\nbar",
+			ExpectedHTML: "<blockquote><blockquote><blockquote><p>foo\nbar</p></blockquote></blockquote></blockquote>",
+		},
+		"0.28-gfm-222": {
+			Markdown:     ">>> foo\n> bar\n>>baz",
+			ExpectedHTML: "<blockquote><blockquote><blockquote><p>foo\nbar\nbaz</p></blockquote></blockquote></blockquote>",
+		},
+		"0.28-gfm-223": {
+			Markdown:     ">     code\n\n>    not code",
+			ExpectedHTML: "<blockquote><pre><code>code\n</code></pre></blockquote><blockquote><p>not code</p></blockquote>",
+		},
+		"0.28-gfm-224": {
+			Markdown:     "A paragraph\nwith two lines.\n\n    indented code\n\n> A block quote.",
+			ExpectedHTML: "<p>A paragraph\nwith two lines.</p><pre><code>indented code\n</code></pre><blockquote><p>A block quote.</p></blockquote>",
+		},
+		"0.28-gfm-225": {
+			Markdown:     "1.  A paragraph\n    with two lines.\n\n        indented code\n\n    > A block quote.",
+			ExpectedHTML: "<ol><li><p>A paragraph\nwith two lines.</p><pre><code>indented code\n</code></pre><blockquote><p>A block quote.</p></blockquote></li></ol>",
+		},
+		"0.28-gfm-226": {
+			Markdown:     "- one\n\n two",
+			ExpectedHTML: "<ul><li>one</li></ul><p>two</p>",
+		},
+		"0.28-gfm-227": {
+			Markdown:     "- one\n\n  two",
+			ExpectedHTML: "<ul><li><p>one</p><p>two</p></li></ul>",
+		},
+		"0.28-gfm-228": {
+			Markdown:     " -    one\n\n     two",
+			ExpectedHTML: "<ul><li>one</li></ul><pre><code> two</code></pre>",
+		},
+		"0.28-gfm-229": {
+			Markdown:     " -    one\n\n      two",
+			ExpectedHTML: "<ul><li><p>one</p><p>two</p></li></ul>",
+		},
+		"0.28-gfm-230": {
+			Markdown:     "   > > 1.  one\n>>\n>>     two",
+			ExpectedHTML: "<blockquote><blockquote><ol><li><p>one</p><p>two</p></li></ol></blockquote></blockquote>",
+		},
+		"0.28-gfm-231": {
+			Markdown:     ">>- one\n>>\n  >  > two",
+			ExpectedHTML: "<blockquote><blockquote><ul><li>one</li></ul><p>two</p></blockquote></blockquote>",
+		},
+		"0.28-gfm-232": {
+			Markdown:     "-one\n\n2.two",
+			ExpectedHTML: "<p>-one</p><p>2.two</p>",
+		},
+		"0.28-gfm-233": {
+			Markdown:     "- foo\n\n\n  bar",
+			ExpectedHTML: "<ul><li><p>foo</p><p>bar</p></li></ul>",
+		},
+		"0.28-gfm-234": {
+			Markdown:     "1.  foo\n\n    ```\n    bar\n    ```\n\n    baz\n\n    > bam",
+			ExpectedHTML: "<ol><li><p>foo</p><pre><code>bar\n</code></pre><p>baz</p><blockquote><p>bam</p></blockquote></li></ol>",
+		},
+		"0.28-gfm-235": {
+			Markdown:     "- Foo\n\n      bar\n\n\n      baz",
+			ExpectedHTML: "<ul><li><p>Foo</p><pre><code>bar\n\n\nbaz</code></pre></li></ul>",
+		},
+		"0.28-gfm-236": {
+			Markdown:     "123456789. ok",
+			ExpectedHTML: `<ol start="123456789"><li>ok</li></ol>`,
+		},
+		"0.28-gfm-237": {
+			Markdown:     "1234567890. not ok",
+			ExpectedHTML: "<p>1234567890. not ok</p>",
+		},
+		"0.28-gfm-238": {
+			Markdown:     "0. ok",
+			ExpectedHTML: `<ol start="0"><li>ok</li></ol>`,
+		},
+		"0.28-gfm-239": {
+			Markdown:     "003. ok",
+			ExpectedHTML: `<ol start="3"><li>ok</li></ol>`,
+		},
+		"0.28-gfm-240": {
+			Markdown:     "-1. not ok",
+			ExpectedHTML: "<p>-1. not ok</p>",
+		},
+		"0.28-gfm-241": {
+			Markdown:     "- foo\n\n      bar",
+			ExpectedHTML: "<ul><li><p>foo</p><pre><code>bar</code></pre></li></ul>",
+		},
+		"0.28-gfm-242": {
+			Markdown:     "  10.  foo\n\n           bar",
+			ExpectedHTML: `<ol start="10"><li><p>foo</p><pre><code>bar</code></pre></li></ol>`,
+		},
+		"0.28-gfm-243": {
+			Markdown:     "    indented code\n\nparagraph\n\n    more code",
+			ExpectedHTML: "<pre><code>indented code\n</code></pre><p>paragraph</p><pre><code>more code</code></pre>",
+		},
+		"0.28-gfm-244": {
+			Markdown:     "1.     indented code\n\n   paragraph\n\n       more code",
+			ExpectedHTML: "<ol><li><pre><code>indented code\n</code></pre><p>paragraph</p><pre><code>more code</code></pre></li></ol>",
+		},
+		"0.28-gfm-245": {
+			Markdown:     "1.      indented code\n\n   paragraph\n\n       more code",
+			ExpectedHTML: "<ol><li><pre><code> indented code\n</code></pre><p>paragraph</p><pre><code>more code</code></pre></li></ol>",
+		},
+		"0.28-gfm-246": {
+			Markdown:     "   foo\n\nbar",
+			ExpectedHTML: "<p>foo</p><p>bar</p>",
+		},
+		"0.28-gfm-247": {
+			Markdown:     "-    foo\n\n  bar",
+			ExpectedHTML: "<ul><li>foo</li></ul><p>bar</p>",
+		},
+		"0.28-gfm-248": {
+			Markdown:     "-  foo\n\n   bar",
+			ExpectedHTML: "<ul><li><p>foo</p><p>bar</p></li></ul>",
+		},
+		"0.28-gfm-249": {
+			Markdown:     "-\n  foo\n-\n  ```\n  bar\n  ```\n-\n      baz",
+			ExpectedHTML: "<ul><li>foo</li><li><pre><code>bar\n</code></pre></li><li><pre><code>baz</code></pre></li></ul>",
+		},
+		"0.28-gfm-250": {
+			Markdown:     "-   \n  foo",
+			ExpectedHTML: "<ul><li>foo</li></ul>",
+		},
+		"0.28-gfm-251": {
+			Markdown:     "-\n\n  foo",
+			ExpectedHTML: "<ul><li></li></ul><p>foo</p>",
+		},
+		"0.28-gfm-252": {
+			Markdown:     "- foo\n-\n- bar",
+			ExpectedHTML: "<ul><li>foo</li><li></li><li>bar</li></ul>",
+		},
+		"0.28-gfm-253": {
+			Markdown:     "- foo\n-   \n- bar",
+			ExpectedHTML: "<ul><li>foo</li><li></li><li>bar</li></ul>",
+		},
+		"0.28-gfm-254": {
+			Markdown:     "1. foo\n2.\n3. bar",
+			ExpectedHTML: "<ol><li>foo</li><li></li><li>bar</li></ol>",
+		},
+		"0.28-gfm-255": {
+			Markdown:     "*",
+			ExpectedHTML: "<ul><li></li></ul>",
+		},
+		"0.28-gfm-256": {
+			Markdown:     "foo\n*\n\nfoo\n1.",
+			ExpectedHTML: "<p>foo\n*</p><p>foo\n1.</p>",
+		},
+		"0.28-gfm-257": {
+			Markdown:     " 1.  A paragraph\n     with two lines.\n\n         indented code\n\n     > A block quote.",
+			ExpectedHTML: "<ol><li><p>A paragraph\nwith two lines.</p><pre><code>indented code\n</code></pre><blockquote><p>A block quote.</p></blockquote></li></ol>",
+		},
+		"0.28-gfm-258": {
+			Markdown:     "  1.  A paragraph\n      with two lines.\n\n          indented code\n\n      > A block quote.",
+			ExpectedHTML: "<ol><li><p>A paragraph\nwith two lines.</p><pre><code>indented code\n</code></pre><blockquote><p>A block quote.</p></blockquote></li></ol>",
+		},
+		"0.28-gfm-259": {
+			Markdown:     "   1.  A paragraph\n       with two lines.\n\n           indented code\n\n       > A block quote.",
+			ExpectedHTML: "<ol><li><p>A paragraph\nwith two lines.</p><pre><code>indented code\n</code></pre><blockquote><p>A block quote.</p></blockquote></li></ol>",
+		},
+		"0.28-gfm-260": {
+			Markdown:     "    1.  A paragraph\n        with two lines.\n\n            indented code\n\n        > A block quote.",
+			ExpectedHTML: "<pre><code>1.  A paragraph\n    with two lines.\n\n        indented code\n\n    &gt; A block quote.</code></pre>",
+		},
+		"0.28-gfm-261": {
+			Markdown:     "  1.  A paragraph\nwith two lines.\n\n          indented code\n\n      > A block quote.",
+			ExpectedHTML: "<ol><li><p>A paragraph\nwith two lines.</p><pre><code>indented code\n</code></pre><blockquote><p>A block quote.</p></blockquote></li></ol>",
+		},
+		"0.28-gfm-262": {
+			Markdown:     "  1.  A paragraph\n    with two lines.",
+			ExpectedHTML: "<ol><li>A paragraph\nwith two lines.</li></ol>",
+		},
+		"0.28-gfm-263": {
+			Markdown:     "> 1. > Blockquote\ncontinued here.",
+			ExpectedHTML: "<blockquote><ol><li><blockquote><p>Blockquote\ncontinued here.</p></blockquote></li></ol></blockquote>",
+		},
+		"0.28-gfm-264": {
+			Markdown:     "> 1. > Blockquote\n> continued here.",
+			ExpectedHTML: "<blockquote><ol><li><blockquote><p>Blockquote\ncontinued here.</p></blockquote></li></ol></blockquote>",
+		},
+		"0.28-gfm-265": {
+			Markdown:     "- foo\n  - bar\n    - baz\n      - boo",
+			ExpectedHTML: "<ul><li>foo<ul><li>bar<ul><li>baz<ul><li>boo</li></ul></li></ul></li></ul></li></ul>",
+		},
+		"0.28-gfm-266": {
+			Markdown:     "- foo\n - bar\n  - baz\n   - boo",
+			ExpectedHTML: "<ul><li>foo</li><li>bar</li><li>baz</li><li>boo</li></ul>",
+		},
+		"0.28-gfm-267": {
+			Markdown:     "10) foo\n    - bar",
+			ExpectedHTML: `<ol start="10"><li>foo<ul><li>bar</li></ul></li></ol>`,
+		},
+		"0.28-gfm-268": {
+			Markdown:     "10) foo\n   - bar",
+			ExpectedHTML: `<ol start="10"><li>foo</li></ol><ul><li>bar</li></ul>`,
+		},
+		"0.28-gfm-269": {
+			Markdown:     "- - foo",
+			ExpectedHTML: "<ul><li><ul><li>foo</li></ul></li></ul>",
+		},
+		"0.28-gfm-270": {
+			Markdown:     "1. - 2. foo",
+			ExpectedHTML: `<ol><li><ul><li><ol start="2"><li>foo</li></ol></li></ul></li></ol>`,
+		},
+		"0.28-gfm-274": {
+			Markdown:     "- foo\n- bar\n+ baz",
+			ExpectedHTML: "<ul><li>foo</li><li>bar</li></ul><ul><li>baz</li></ul>",
+		},
+		"0.28-gfm-275": {
+			Markdown:     "1. foo\n2. bar\n3) baz",
+			ExpectedHTML: `<ol><li>foo</li><li>bar</li></ol><ol start="3"><li>baz</li></ol>`,
+		},
+		"0.28-gfm-276": {
+			Markdown:     "Foo\n- bar\n- baz",
+			ExpectedHTML: "<p>Foo</p><ul><li>bar</li><li>baz</li></ul>",
+		},
+		"0.28-gfm-277": {
+			Markdown:     "The number of windows in my house is\n14.  The number of doors is 6.",
+			ExpectedHTML: "<p>The number of windows in my house is\n14.  The number of doors is 6.</p>",
+		},
+		"0.28-gfm-278": {
+			Markdown:     "The number of windows in my house is\n1.  The number of doors is 6.",
+			ExpectedHTML: "<p>The number of windows in my house is</p><ol><li>The number of doors is 6.</li></ol>",
+		},
+		"0.28-gfm-279": {
+			Markdown:     "- foo\n\n- bar\n\n\n- baz",
+			ExpectedHTML: "<ul><li><p>foo</p></li><li><p>bar</p></li><li><p>baz</p></li></ul>",
+		},
+		"0.28-gfm-280": {
+			Markdown:     "- foo\n  - bar\n    - baz\n\n\n      bim",
+			ExpectedHTML: "<ul><li>foo<ul><li>bar<ul><li><p>baz</p><p>bim</p></li></ul></li></ul></li></ul>",
+		},
+		"0.28-gfm-283": {
+			Markdown:     "- a\n - b\n  - c\n   - d\n    - e\n   - f\n  - g\n - h\n- i",
+			ExpectedHTML: "<ul><li>a</li><li>b</li><li>c</li><li>d</li><li>e</li><li>f</li><li>g</li><li>h</li><li>i</li></ul>",
+		},
+		"0.28-gfm-284": {
+			Markdown:     "1. a\n\n  2. b\n\n    3. c",
+			ExpectedHTML: "<ol><li><p>a</p></li><li><p>b</p></li><li><p>c</p></li></ol>",
+		},
+		"0.28-gfm-285": {
+			Markdown:     "- a\n- b\n\n- c",
+			ExpectedHTML: "<ul><li><p>a</p></li><li><p>b</p></li><li><p>c</p></li></ul>",
+		},
+		"0.28-gfm-286": {
+			Markdown:     "* a\n*\n\n* c",
+			ExpectedHTML: "<ul><li><p>a</p></li><li></li><li><p>c</p></li></ul>",
+		},
+		"0.28-gfm-287": {
+			Markdown:     "- a\n- b\n\n  c\n- d",
+			ExpectedHTML: "<ul><li><p>a</p></li><li><p>b</p><p>c</p></li><li><p>d</p></li></ul>",
+		},
+		"0.28-gfm-288": {
+			Markdown:     "- a\n- b\n\n  [ref]: /url\n- d",
+			ExpectedHTML: "<ul><li><p>a</p></li><li><p>b</p></li><li><p>d</p></li></ul>",
+		},
+		"0.28-gfm-289": {
+			Markdown:     "- a\n- ```\n  b\n\n\n  ```\n- c",
+			ExpectedHTML: "<ul><li>a</li><li><pre><code>b\n\n\n</code></pre></li><li>c</li></ul>",
+		},
+		"0.28-gfm-290": {
+			Markdown:     "- a\n  - b\n\n    c\n- d",
+			ExpectedHTML: "<ul><li>a<ul><li><p>b</p><p>c</p></li></ul></li><li>d</li></ul>",
+		},
+		"0.28-gfm-291": {
+			Markdown:     "* a\n  > b\n  >\n* c",
+			ExpectedHTML: "<ul><li>a<blockquote><p>b</p></blockquote></li><li>c</li></ul>",
+		},
+		"0.28-gfm-292": {
+			Markdown:     "- a\n  > b\n  ```\n  c\n  ```\n- d",
+			ExpectedHTML: "<ul><li>a<blockquote><p>b</p></blockquote><pre><code>c\n</code></pre></li><li>d</li></ul>",
+		},
+		"0.28-gfm-293": {
+			Markdown:     "- a",
+			ExpectedHTML: "<ul><li>a</li></ul>",
+		},
+		"0.28-gfm-294": {
+			Markdown:     "- a\n  - b",
+			ExpectedHTML: "<ul><li>a<ul><li>b</li></ul></li></ul>",
+		},
+		"0.28-gfm-295": {
+			Markdown:     "1. ```\n   foo\n   ```\n\n   bar",
+			ExpectedHTML: "<ol><li><pre><code>foo\n</code></pre><p>bar</p></li></ol>",
+		},
+		"0.28-gfm-296": {
+			Markdown:     "* foo\n  * bar\n\n  baz",
+			ExpectedHTML: "<ul><li><p>foo</p><ul><li>bar</li></ul><p>baz</p></li></ul>",
+		},
+		"0.28-gfm-297": {
+			Markdown:     "- a\n  - b\n  - c\n\n- d\n  - e\n  - f",
+			ExpectedHTML: "<ul><li><p>a</p><ul><li>b</li><li>c</li></ul></li><li><p>d</p><ul><li>e</li><li>f</li></ul></li></ul>",
+		},
+		"0.28-gfm-298": {
+			Markdown:     "`hi`lo`",
+			ExpectedHTML: "<p><code>hi</code>lo`</p>",
+		},
+		"0.28-gfm-299": {
+			Markdown:     `\!\"\#\$\%\&\'\(\)\*\+\,\-\.\/\:\;\<\=\>\?\@\[\\\]\^\_` + "\\`" + `\{\|\}\~`,
+			ExpectedHTML: "<p>!&quot;#$%&amp;'()*+,-./:;&lt;=&gt;?@[\\]^_`{|}~</p>",
+		},
+		"0.28-gfm-300": {
+			Markdown:     `\→\A\a\ \3\φ\«`,
+			ExpectedHTML: `<p>\→\A\a\ \3\φ\«</p>`,
+		},
+		"0.28-gfm-301": {
+			Markdown: `\*not emphasized*
+\<br/> not a tag
+\[not a link](/foo)
+\` + "`not code`" + `
+1\. not a list
+\* not a list
+\# not a heading
+\[foo]: /url "not a reference"`,
+			ExpectedHTML: `<p>*not emphasized*
+&lt;br/&gt; not a tag
+[not a link](/foo)
+` + "`not code`" + `
+1. not a list
+* not a list
+# not a heading
+[foo]: /url &quot;not a reference&quot;</p>`,
+		},
+		"0.28-gfm-304": {
+			Markdown:     "`` \\[\\` ``",
+			ExpectedHTML: "<p><code>\\[\\`</code></p>",
+		},
+		"0.28-gfm-305": {
+			Markdown:     `    \[\]`,
+			ExpectedHTML: `<pre><code>\[\]</code></pre>`,
+		},
+		"0.28-gfm-306": {
+			Markdown:     "~~~\n\\[\\]\n~~~",
+			ExpectedHTML: "<pre><code>\\[\\]\n</code></pre>",
+		},
+		"0.28-gfm-309": {
+			Markdown:     `[foo](/bar\* "ti\*tle")`,
+			ExpectedHTML: `<p><a href="/bar*" title="ti*tle">foo</a></p>`,
+		},
+		"0.28-gfm-310": {
+			Markdown: `[foo]
+
+[foo]: /bar\* "ti\*tle"`,
+			ExpectedHTML: `<p><a href="/bar*" title="ti*tle">foo</a></p>`,
+		},
+		"0.28-gfm-311": {
+			Markdown:     "``` foo\\+bar\nfoo\n```",
+			ExpectedHTML: "<pre><code class=\"language-foo+bar\">foo\n</code></pre>",
+		},
+		"0.28-gfm-312": {
+			Markdown:     "&nbsp; &amp; &copy; &AElig; &Dcaron;\n&frac34; &HilbertSpace; &DifferentialD;\n&ClockwiseContourIntegral; &ngE;",
+			ExpectedHTML: "<p>\u00a0 &amp; © Æ Ď\n¾ ℋ ⅆ\n∲ ≧̸</p>",
+		},
+		"0.28-gfm-313": {
+			Markdown:     "&#35; &#1234; &#992; &#98765432; &#0;",
+			ExpectedHTML: "<p># Ӓ Ϡ � �</p>",
+		},
+		"0.28-gfm-314": {
+			Markdown:     "&#X22; &#XD06; &#xcab;",
+			ExpectedHTML: "<p>&quot; ആ ಫ</p>",
+		},
+		"0.28-gfm-315": {
+			Markdown:     "&nbsp &x; &#; &#x;\n&ThisIsNotDefined; &hi?;",
+			ExpectedHTML: "<p>&amp;nbsp &amp;x; &amp;#; &amp;#x;\n&amp;ThisIsNotDefined; &amp;hi?;</p>",
+		},
+		"0.28-gfm-316": {
+			Markdown:     "&copy",
+			ExpectedHTML: "<p>&amp;copy</p>",
+		},
+		"0.28-gfm-317": {
+			Markdown:     "&MadeUpEntity;",
+			ExpectedHTML: "<p>&amp;MadeUpEntity;</p>",
+		},
+		"0.28-gfm-319": {
+			Markdown:     `[foo](/f&ouml;&ouml; "f&ouml;&ouml;")`,
+			ExpectedHTML: `<p><a href="/f%C3%B6%C3%B6" title="föö">foo</a></p>`,
+		},
+		"0.28-gfm-320": {
+			Markdown:     "[foo]\n\n[foo]: /f&ouml;&ouml; \"f&ouml;&ouml;\"",
+			ExpectedHTML: `<p><a href="/f%C3%B6%C3%B6" title="föö">foo</a></p>`,
+		},
+		"0.28-gfm-321": {
+			Markdown:     "``` f&ouml;&ouml;\nfoo\n```",
+			ExpectedHTML: "<pre><code class=\"language-föö\">foo\n</code></pre>",
+		},
+		"0.28-gfm-322": {
+			Markdown:     "`f&ouml;&ouml;`",
+			ExpectedHTML: "<p><code>f&amp;ouml;&amp;ouml;</code></p>",
+		},
+		"0.28-gfm-323": {
+			Markdown:     "    f&ouml;f&ouml;",
+			ExpectedHTML: "<pre><code>f&amp;ouml;f&amp;ouml;</code></pre>",
+		},
+		"0.28-gfm-324": {
+			Markdown:     "`foo`",
+			ExpectedHTML: "<p><code>foo</code></p>",
+		},
+		"0.28-gfm-325": {
+			Markdown:     "`` foo ` bar ``",
+			ExpectedHTML: "<p><code>foo ` bar</code></p>",
+		},
+		"0.28-gfm-326": {
+			Markdown:     "` `` `",
+			ExpectedHTML: "<p><code>``</code></p>",
+		},
+		"0.28-gfm-327": {
+			Markdown:     "``\nfoo\n``",
+			ExpectedHTML: "<p><code>foo</code></p>",
+		},
+		"0.28-gfm-328": {
+			Markdown:     "`foo   bar\n  baz`",
+			ExpectedHTML: "<p><code>foo bar baz</code></p>",
+		},
+		"0.28-gfm-329": {
+			Markdown:     "`a\xa0\xa0b`",
+			ExpectedHTML: "<p><code>a\xa0\xa0b</code></p>",
+		},
+		"0.28-gfm-330": {
+			Markdown:     "`foo `` bar`",
+			ExpectedHTML: "<p><code>foo `` bar</code></p>",
+		},
+		"0.28-gfm-331": {
+			Markdown:     "`foo\\`bar`",
+			ExpectedHTML: "<p><code>foo\\</code>bar`</p>",
+		},
+		"0.28-gfm-332": {
+			Markdown:     "*foo`*`",
+			ExpectedHTML: "<p>*foo<code>*</code></p>",
+		},
+		"0.28-gfm-333": {
+			Markdown:     "[not a `link](/foo`)",
+			ExpectedHTML: "<p>[not a <code>link](/foo</code>)</p>",
+		},
+		"0.28-gfm-334": {
+			Markdown:     "`<a href=\"`\">`",
+			ExpectedHTML: "<p><code>&lt;a href=&quot;</code>&quot;&gt;`</p>",
+		},
+		"0.28-gfm-336": {
+			Markdown:     "`<http://foo.bar.`baz>`",
+			ExpectedHTML: "<p><code>&lt;http://foo.bar.</code>baz&gt;`</p>",
+		},
+		"0.28-gfm-338": {
+			Markdown:     "```foo``",
+			ExpectedHTML: "<p>```foo``</p>",
+		},
+		"0.28-gfm-339": {
+			Markdown:     "`foo",
+			ExpectedHTML: "<p>`foo</p>",
+		},
+		"0.28-gfm-340": {
+			Markdown:     "`foo``bar``",
+			ExpectedHTML: "<p>`foo<code>bar</code></p>",
+		},
+		"0.28-gfm-472": {
+			Markdown:     `[link](/uri "title")`,
+			ExpectedHTML: `<p><a href="/uri" title="title">link</a></p>`,
+		},
+		"0.28-gfm-473": {
+			Markdown:     `[link](/uri)`,
+			ExpectedHTML: `<p><a href="/uri">link</a></p>`,
+		},
+		"0.28-gfm-474": {
+			Markdown:     `[link]()`,
+			ExpectedHTML: `<p><a href="">link</a></p>`,
+		},
+		"0.28-gfm-475": {
+			Markdown:     `[link](<>)`,
+			ExpectedHTML: `<p><a href="">link</a></p>`,
+		},
+		"0.28-gfm-476": {
+			Markdown:     `[link](/my uri)`,
+			ExpectedHTML: `<p>[link](/my uri)</p>`,
+		},
+		"0.28-gfm-477": {
+			Markdown:     `[link](</my uri>)`,
+			ExpectedHTML: `<p>[link](&lt;/my uri&gt;)</p>`,
+		},
+		"0.28-gfm-478": {
+			Markdown:     "[link](foo\nbar)",
+			ExpectedHTML: "<p>[link](foo\nbar)</p>",
+		},
+		"0.28-gfm-480": {
+			Markdown:     `[link](\(foo\))`,
+			ExpectedHTML: `<p><a href="(foo)">link</a></p>`,
+		},
+		"0.28-gfm-481": {
+			Markdown:     `[link](foo(and(bar)))`,
+			ExpectedHTML: `<p><a href="foo(and(bar))">link</a></p>`,
+		},
+		"0.28-gfm-482": {
+			Markdown:     `[link](foo\(and\(bar\))`,
+			ExpectedHTML: `<p><a href="foo(and(bar)">link</a></p>`,
+		},
+		"0.28-gfm-483": {
+			Markdown:     `[link](<foo(and(bar)>)`,
+			ExpectedHTML: `<p><a href="foo(and(bar)">link</a></p>`,
+		},
+		"0.28-gfm-484": {
+			Markdown:     `[link](foo\)\:)`,
+			ExpectedHTML: `<p><a href="foo):">link</a></p>`,
+		},
+		"0.28-gfm-485": {
+			Markdown:     "[link](#fragment)\n\n[link](http://example.com#fragment)\n\n[link](http://example.com?foo=3#frag)",
+			ExpectedHTML: `<p><a href="#fragment">link</a></p><p><a href="http://example.com#fragment">link</a></p><p><a href="http://example.com?foo=3#frag">link</a></p>`,
+		},
+		"0.28-gfm-486": {
+			Markdown:     `[link](foo\bar)`,
+			ExpectedHTML: `<p><a href="foo%5Cbar">link</a></p>`,
+		},
+		"0.28-gfm-488": {
+			Markdown:     `[link]("title")`,
+			ExpectedHTML: `<p><a href="%22title%22">link</a></p>`,
+		},
+		"0.28-gfm-489": {
+			Markdown:     "[link](/url \"title\")\n[link](/url 'title')\n[link](/url (title))",
+			ExpectedHTML: "<p><a href=\"/url\" title=\"title\">link</a>\n<a href=\"/url\" title=\"title\">link</a>\n<a href=\"/url\" title=\"title\">link</a></p>",
+		},
+		"0.28-gfm-490": {
+			Markdown:     `[link](/url "title \"&quot;")`,
+			ExpectedHTML: `<p><a href="/url" title="title &quot;&quot;">link</a></p>`,
+		},
+		"0.28-gfm-491": {
+			Markdown:     "[link](/url\u00a0\"title\")",
+			ExpectedHTML: `<p><a href="/url%C2%A0%22title%22">link</a></p>`,
+		},
+		"0.28-gfm-492": {
+			Markdown:     `[link](/url "title "and" title")`,
+			ExpectedHTML: `<p>[link](/url &quot;title &quot;and&quot; title&quot;)</p>`,
+		},
+		"0.28-gfm-493": {
+			Markdown:     `[link](/url 'title "and" title')`,
+			ExpectedHTML: `<p><a href="/url" title="title &quot;and&quot; title">link</a></p>`,
+		},
+		"0.28-gfm-494": {
+			Markdown:     "[link](   /uri\n  \"title\"  )",
+			ExpectedHTML: `<p><a href="/uri" title="title">link</a></p>`,
+		},
+		"0.28-gfm-495": {
+			Markdown:     "[link] (/uri)",
+			ExpectedHTML: `<p>[link] (/uri)</p>`,
+		},
+		"0.28-gfm-496": {
+			Markdown:     "[link [foo [bar]]](/uri)",
+			ExpectedHTML: `<p><a href="/uri">link [foo [bar]]</a></p>`,
+		},
+		"0.28-gfm-497": {
+			Markdown:     "[link] bar](/uri)",
+			ExpectedHTML: `<p>[link] bar](/uri)</p>`,
+		},
+		"0.28-gfm-498": {
+			Markdown:     "[link [bar](/uri)",
+			ExpectedHTML: `<p>[link <a href="/uri">bar</a></p>`,
+		},
+		"0.28-gfm-499": {
+			Markdown:     `[link \[bar](/uri)`,
+			ExpectedHTML: `<p><a href="/uri">link [bar</a></p>`,
+		},
+		"0.28-gfm-501": {
+			Markdown:     "[![moon](moon.jpg)](/uri)",
+			ExpectedHTML: `<p><a href="/uri"><img src="moon.jpg" alt="moon" /></a></p>`,
+		},
+		"0.28-gfm-502": {
+			Markdown:     "[foo [bar](/uri)](/uri)",
+			ExpectedHTML: `<p>[foo <a href="/uri">bar</a>](/uri)</p>`,
+		},
+		"0.28-gfm-504": {
+			Markdown:     "![[[foo](uri1)](uri2)](uri3)",
+			ExpectedHTML: `<p><img src="uri3" alt="[foo](uri2)" /></p>`,
+		},
+		"0.28-gfm-505": {
+			Markdown:     "*[foo*](/uri)",
+			ExpectedHTML: `<p>*<a href="/uri">foo*</a></p>`,
+		},
+		"0.28-gfm-506": {
+			Markdown:     "[foo *bar](baz*)",
+			ExpectedHTML: `<p><a href="baz*">foo *bar</a></p>`,
+		},
+		"0.28-gfm-509": {
+			Markdown:     "[foo`](/uri)`",
+			ExpectedHTML: `<p>[foo<code>](/uri)</code></p>`,
+		},
+		"0.28-gfm-556": {
+			Markdown:     `![foo](/url "title")`,
+			ExpectedHTML: `<p><img src="/url" alt="foo" title="title" /></p>`,
+		},
+		"0.28-gfm-558": {
+			Markdown:     `![foo ![bar](/url)](/url2)`,
+			ExpectedHTML: `<p><img src="/url2" alt="foo bar" /></p>`,
+		},
+		"0.28-gfm-559": {
+			Markdown:     `![foo [bar](/url)](/url2)`,
+			ExpectedHTML: `<p><img src="/url2" alt="foo bar" /></p>`,
+		},
+		"0.28-gfm-562": {
+			Markdown:     `![foo](train.jpg)`,
+			ExpectedHTML: `<p><img src="train.jpg" alt="foo" /></p>`,
+		},
+		"0.28-gfm-563": {
+			Markdown:     `My ![foo bar](/path/to/train.jpg  "title"   )`,
+			ExpectedHTML: `<p>My <img src="/path/to/train.jpg" alt="foo bar" title="title" /></p>`,
+		},
+		"0.28-gfm-564": {
+			Markdown:     `![foo](<url>)`,
+			ExpectedHTML: `<p><img src="url" alt="foo" /></p>`,
+		},
+		"0.28-gfm-565": {
+			Markdown:     `![](/url)`,
+			ExpectedHTML: `<p><img src="/url" alt="" /></p>`,
+		},
+		"0.28-gfm-647": {
+			Markdown:     "hello $.;'there",
+			ExpectedHTML: "<p>hello $.;'there</p>",
+		},
+		"0.28-gfm-648": {
+			Markdown:     "Foo χρῆν",
+			ExpectedHTML: "<p>Foo χρῆν</p>",
+		},
+		"0.28-gfm-649": {
+			Markdown:     "Multiple     spaces",
+			ExpectedHTML: "<p>Multiple     spaces</p>",
+		},
+	} {
+		t.Run(name, func(t *testing.T) {
+			assert.Equal(t, tc.ExpectedHTML, RenderHTML(tc.Markdown))
+		})
+	}
+}
diff --git a/utils/markdown/document.go b/utils/markdown/document.go
new file mode 100644
index 000000000..224b5d215
--- /dev/null
+++ b/utils/markdown/document.go
@@ -0,0 +1,22 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+type Document struct {
+	blockBase
+
+	Children []Block
+}
+
+func (b *Document) Continuation(indentation int, r Range) *continuation {
+	return &continuation{
+		Indentation: indentation,
+		Remaining:   r,
+	}
+}
+
+func (b *Document) AddChild(openBlocks []Block) []Block {
+	b.Children = append(b.Children, openBlocks[0])
+	return openBlocks
+}
diff --git a/utils/markdown/fenced_code.go b/utils/markdown/fenced_code.go
new file mode 100644
index 000000000..8b2ebd4fe
--- /dev/null
+++ b/utils/markdown/fenced_code.go
@@ -0,0 +1,112 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type FencedCodeLine struct {
+	Indentation int
+	Range       Range
+}
+
+type FencedCode struct {
+	blockBase
+	markdown           string
+	didSeeClosingFence bool
+
+	Indentation  int
+	OpeningFence Range
+	RawInfo      Range
+	RawCode      []FencedCodeLine
+}
+
+func (b *FencedCode) Code() (result string) {
+	for _, code := range b.RawCode {
+		result += strings.Repeat(" ", code.Indentation) + b.markdown[code.Range.Position:code.Range.End]
+	}
+	return
+}
+
+func (b *FencedCode) Info() string {
+	return Unescape(b.markdown[b.RawInfo.Position:b.RawInfo.End])
+}
+
+func (b *FencedCode) Continuation(indentation int, r Range) *continuation {
+	if b.didSeeClosingFence {
+		return nil
+	}
+	return &continuation{
+		Indentation: indentation,
+		Remaining:   r,
+	}
+}
+
+func (b *FencedCode) AddLine(indentation int, r Range) bool {
+	s := b.markdown[r.Position:r.End]
+	if indentation <= 3 && strings.HasPrefix(s, b.markdown[b.OpeningFence.Position:b.OpeningFence.End]) {
+		suffix := strings.TrimSpace(s[b.OpeningFence.End-b.OpeningFence.Position:])
+		isClosingFence := true
+		for _, c := range suffix {
+			if c != rune(s[0]) {
+				isClosingFence = false
+				break
+			}
+		}
+		if isClosingFence {
+			b.didSeeClosingFence = true
+			return true
+		}
+	}
+
+	if indentation >= b.Indentation {
+		indentation -= b.Indentation
+	} else {
+		indentation = 0
+	}
+
+	b.RawCode = append(b.RawCode, FencedCodeLine{
+		Indentation: indentation,
+		Range:       r,
+	})
+	return true
+}
+
+func (b *FencedCode) AllowsBlockStarts() bool {
+	return false
+}
+
+func fencedCodeStart(markdown string, indentation int, r Range, matchedBlocks, unmatchedBlocks []Block) []Block {
+	s := markdown[r.Position:r.End]
+
+	if !strings.HasPrefix(s, "```") && !strings.HasPrefix(s, "~~~") {
+		return nil
+	}
+
+	fenceCharacter := rune(s[0])
+	fenceLength := 3
+	for _, c := range s[3:] {
+		if c == fenceCharacter {
+			fenceLength++
+		} else {
+			break
+		}
+	}
+
+	for i := r.Position + fenceLength; i < r.End; i++ {
+		if markdown[i] == '`' {
+			return nil
+		}
+	}
+
+	return []Block{
+		&FencedCode{
+			markdown:     markdown,
+			Indentation:  indentation,
+			RawInfo:      trimRightSpace(markdown, Range{r.Position + fenceLength, r.End}),
+			OpeningFence: Range{r.Position, r.Position + fenceLength},
+		},
+	}
+}
diff --git a/utils/markdown/html.go b/utils/markdown/html.go
new file mode 100644
index 000000000..8d8e02c55
--- /dev/null
+++ b/utils/markdown/html.go
@@ -0,0 +1,186 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"fmt"
+	"strings"
+)
+
+var htmlEscaper = strings.NewReplacer(
+	`&`, "&amp;",
+	`<`, "&lt;",
+	`>`, "&gt;",
+	`"`, "&quot;",
+)
+
+// RenderHTML produces HTML with the same behavior as the example renderer used in the CommonMark
+// reference materials except for one slight difference: for brevity, no unnecessary whitespace is
+// inserted between elements. The output is not defined by the CommonMark spec, and it exists
+// primarily as an aid in testing.
+func RenderHTML(markdown string) string {
+	return RenderBlockHTML(Parse(markdown))
+}
+
+func RenderBlockHTML(block Block, referenceDefinitions []*ReferenceDefinition) (result string) {
+	return renderBlockHTML(block, referenceDefinitions, false)
+}
+
+func renderBlockHTML(block Block, referenceDefinitions []*ReferenceDefinition, isTightList bool) (result string) {
+	switch v := block.(type) {
+	case *Document:
+		for _, block := range v.Children {
+			result += RenderBlockHTML(block, referenceDefinitions)
+		}
+	case *Paragraph:
+		if len(v.Text) == 0 {
+			return
+		}
+		if !isTightList {
+			result += "<p>"
+		}
+		for _, inline := range v.ParseInlines(referenceDefinitions) {
+			result += RenderInlineHTML(inline)
+		}
+		if !isTightList {
+			result += "</p>"
+		}
+	case *List:
+		if v.IsOrdered {
+			if v.OrderedStart != 1 {
+				result += fmt.Sprintf(`<ol start="%v">`, v.OrderedStart)
+			} else {
+				result += "<ol>"
+			}
+		} else {
+			result += "<ul>"
+		}
+		for _, block := range v.Children {
+			result += renderBlockHTML(block, referenceDefinitions, !v.IsLoose)
+		}
+		if v.IsOrdered {
+			result += "</ol>"
+		} else {
+			result += "</ul>"
+		}
+	case *ListItem:
+		result += "<li>"
+		for _, block := range v.Children {
+			result += renderBlockHTML(block, referenceDefinitions, isTightList)
+		}
+		result += "</li>"
+	case *BlockQuote:
+		result += "<blockquote>"
+		for _, block := range v.Children {
+			result += RenderBlockHTML(block, referenceDefinitions)
+		}
+		result += "</blockquote>"
+	case *FencedCode:
+		if info := v.Info(); info != "" {
+			language := strings.Fields(info)[0]
+			result += `<pre><code class="language-` + htmlEscaper.Replace(language) + `">`
+		} else {
+			result += "<pre><code>"
+		}
+		result += htmlEscaper.Replace(v.Code()) + "</code></pre>"
+	case *IndentedCode:
+		result += "<pre><code>" + htmlEscaper.Replace(v.Code()) + "</code></pre>"
+	default:
+		panic(fmt.Sprintf("missing case for type %T", v))
+	}
+	return
+}
+
+func escapeURL(url string) (result string) {
+	for i := 0; i < len(url); {
+		switch b := url[i]; b {
+		case ';', '/', '?', ':', '@', '&', '=', '+', '$', ',', '-', '_', '.', '!', '~', '*', '\'', '(', ')', '#':
+			result += string(b)
+			i++
+		default:
+			if b == '%' && i+2 < len(url) && isHexByte(url[i+1]) && isHexByte(url[i+2]) {
+				result += url[i : i+3]
+				i += 3
+			} else if (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || (b >= '0' && b <= '9') {
+				result += string(b)
+				i++
+			} else {
+				result += fmt.Sprintf("%%%0X", b)
+				i++
+			}
+		}
+	}
+	return
+}
+
+func RenderInlineHTML(inline Inline) (result string) {
+	switch v := inline.(type) {
+	case *Text:
+		return htmlEscaper.Replace(v.Text)
+	case *HardLineBreak:
+		return "<br />"
+	case *SoftLineBreak:
+		return "\n"
+	case *CodeSpan:
+		return "<code>" + htmlEscaper.Replace(v.Code) + "</code>"
+	case *InlineImage:
+		result += `<img src="` + htmlEscaper.Replace(escapeURL(v.Destination())) + `" alt="` + htmlEscaper.Replace(renderImageAltText(v.Children)) + `"`
+		if title := v.Title(); title != "" {
+			result += ` title="` + htmlEscaper.Replace(title) + `"`
+		}
+		result += ` />`
+	case *ReferenceImage:
+		result += `<img src="` + htmlEscaper.Replace(escapeURL(v.Destination())) + `" alt="` + htmlEscaper.Replace(renderImageAltText(v.Children)) + `"`
+		if title := v.Title(); title != "" {
+			result += ` title="` + htmlEscaper.Replace(title) + `"`
+		}
+		result += ` />`
+	case *InlineLink:
+		result += `<a href="` + htmlEscaper.Replace(escapeURL(v.Destination())) + `"`
+		if title := v.Title(); title != "" {
+			result += ` title="` + htmlEscaper.Replace(title) + `"`
+		}
+		result += `>`
+		for _, inline := range v.Children {
+			result += RenderInlineHTML(inline)
+		}
+		result += "</a>"
+	case *ReferenceLink:
+		result += `<a href="` + htmlEscaper.Replace(escapeURL(v.Destination())) + `"`
+		if title := v.Title(); title != "" {
+			result += ` title="` + htmlEscaper.Replace(title) + `"`
+		}
+		result += `>`
+		for _, inline := range v.Children {
+			result += RenderInlineHTML(inline)
+		}
+		result += "</a>"
+	default:
+		panic(fmt.Sprintf("missing case for type %T", v))
+	}
+	return
+}
+
+func renderImageAltText(children []Inline) (result string) {
+	for _, inline := range children {
+		result += renderImageChildAltText(inline)
+	}
+	return
+}
+
+func renderImageChildAltText(inline Inline) (result string) {
+	switch v := inline.(type) {
+	case *Text:
+		return v.Text
+	case *InlineImage:
+		for _, inline := range v.Children {
+			result += renderImageChildAltText(inline)
+		}
+	case *InlineLink:
+		for _, inline := range v.Children {
+			result += renderImageChildAltText(inline)
+		}
+	}
+	return
+}
diff --git a/utils/markdown/html_entities.go b/utils/markdown/html_entities.go
new file mode 100644
index 000000000..797741de7
--- /dev/null
+++ b/utils/markdown/html_entities.go
@@ -0,0 +1,2132 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+var htmlEntities = map[string]string{
+	"AElig":         "\u00C6",
+	"AMP":           "\u0026",
+	"Aacute":        "\u00C1",
+	"Abreve":        "\u0102",
+	"Acirc":         "\u00C2",
+	"Acy":           "\u0410",
+	"Afr":           "\U0001D504",
+	"Agrave":        "\u00C0",
+	"Alpha":         "\u0391",
+	"Amacr":         "\u0100",
+	"And":           "\u2A53",
+	"Aogon":         "\u0104",
+	"Aopf":          "\U0001D538",
+	"ApplyFunction": "\u2061",
+	"Aring":         "\u00C5",
+	"Ascr":          "\U0001D49C",
+	"Assign":        "\u2254",
+	"Atilde":        "\u00C3",
+	"Auml":          "\u00C4",
+	"Backslash":     "\u2216",
+	"Barv":          "\u2AE7",
+	"Barwed":        "\u2306",
+	"Bcy":           "\u0411",
+	"Because":       "\u2235",
+	"Bernoullis":    "\u212C",
+	"Beta":          "\u0392",
+	"Bfr":           "\U0001D505",
+	"Bopf":          "\U0001D539",
+	"Breve":         "\u02D8",
+	"Bscr":          "\u212C",
+	"Bumpeq":        "\u224E",
+	"CHcy":          "\u0427",
+	"COPY":          "\u00A9",
+	"Cacute":        "\u0106",
+	"Cap":           "\u22D2",
+	"CapitalDifferentialD":            "\u2145",
+	"Cayleys":                         "\u212D",
+	"Ccaron":                          "\u010C",
+	"Ccedil":                          "\u00C7",
+	"Ccirc":                           "\u0108",
+	"Cconint":                         "\u2230",
+	"Cdot":                            "\u010A",
+	"Cedilla":                         "\u00B8",
+	"CenterDot":                       "\u00B7",
+	"Cfr":                             "\u212D",
+	"Chi":                             "\u03A7",
+	"CircleDot":                       "\u2299",
+	"CircleMinus":                     "\u2296",
+	"CirclePlus":                      "\u2295",
+	"CircleTimes":                     "\u2297",
+	"ClockwiseContourIntegral":        "\u2232",
+	"CloseCurlyDoubleQuote":           "\u201D",
+	"CloseCurlyQuote":                 "\u2019",
+	"Colon":                           "\u2237",
+	"Colone":                          "\u2A74",
+	"Congruent":                       "\u2261",
+	"Conint":                          "\u222F",
+	"ContourIntegral":                 "\u222E",
+	"Copf":                            "\u2102",
+	"Coproduct":                       "\u2210",
+	"CounterClockwiseContourIntegral": "\u2233",
+	"Cross":                    "\u2A2F",
+	"Cscr":                     "\U0001D49E",
+	"Cup":                      "\u22D3",
+	"CupCap":                   "\u224D",
+	"DD":                       "\u2145",
+	"DDotrahd":                 "\u2911",
+	"DJcy":                     "\u0402",
+	"DScy":                     "\u0405",
+	"DZcy":                     "\u040F",
+	"Dagger":                   "\u2021",
+	"Darr":                     "\u21A1",
+	"Dashv":                    "\u2AE4",
+	"Dcaron":                   "\u010E",
+	"Dcy":                      "\u0414",
+	"Del":                      "\u2207",
+	"Delta":                    "\u0394",
+	"Dfr":                      "\U0001D507",
+	"DiacriticalAcute":         "\u00B4",
+	"DiacriticalDot":           "\u02D9",
+	"DiacriticalDoubleAcute":   "\u02DD",
+	"DiacriticalGrave":         "\u0060",
+	"DiacriticalTilde":         "\u02DC",
+	"Diamond":                  "\u22C4",
+	"DifferentialD":            "\u2146",
+	"Dopf":                     "\U0001D53B",
+	"Dot":                      "\u00A8",
+	"DotDot":                   "\u20DC",
+	"DotEqual":                 "\u2250",
+	"DoubleContourIntegral":    "\u222F",
+	"DoubleDot":                "\u00A8",
+	"DoubleDownArrow":          "\u21D3",
+	"DoubleLeftArrow":          "\u21D0",
+	"DoubleLeftRightArrow":     "\u21D4",
+	"DoubleLeftTee":            "\u2AE4",
+	"DoubleLongLeftArrow":      "\u27F8",
+	"DoubleLongLeftRightArrow": "\u27FA",
+	"DoubleLongRightArrow":     "\u27F9",
+	"DoubleRightArrow":         "\u21D2",
+	"DoubleRightTee":           "\u22A8",
+	"DoubleUpArrow":            "\u21D1",
+	"DoubleUpDownArrow":        "\u21D5",
+	"DoubleVerticalBar":        "\u2225",
+	"DownArrow":                "\u2193",
+	"DownArrowBar":             "\u2913",
+	"DownArrowUpArrow":         "\u21F5",
+	"DownBreve":                "\u0311",
+	"DownLeftRightVector":      "\u2950",
+	"DownLeftTeeVector":        "\u295E",
+	"DownLeftVector":           "\u21BD",
+	"DownLeftVectorBar":        "\u2956",
+	"DownRightTeeVector":       "\u295F",
+	"DownRightVector":          "\u21C1",
+	"DownRightVectorBar":       "\u2957",
+	"DownTee":                  "\u22A4",
+	"DownTeeArrow":             "\u21A7",
+	"Downarrow":                "\u21D3",
+	"Dscr":                     "\U0001D49F",
+	"Dstrok":                   "\u0110",
+	"ENG":                      "\u014A",
+	"ETH":                      "\u00D0",
+	"Eacute":                   "\u00C9",
+	"Ecaron":                   "\u011A",
+	"Ecirc":                    "\u00CA",
+	"Ecy":                      "\u042D",
+	"Edot":                     "\u0116",
+	"Efr":                      "\U0001D508",
+	"Egrave":                   "\u00C8",
+	"Element":                  "\u2208",
+	"Emacr":                    "\u0112",
+	"EmptySmallSquare":         "\u25FB",
+	"EmptyVerySmallSquare":     "\u25AB",
+	"Eogon":                    "\u0118",
+	"Eopf":                     "\U0001D53C",
+	"Epsilon":                  "\u0395",
+	"Equal":                    "\u2A75",
+	"EqualTilde":               "\u2242",
+	"Equilibrium":              "\u21CC",
+	"Escr":                     "\u2130",
+	"Esim":                     "\u2A73",
+	"Eta":                      "\u0397",
+	"Euml":                     "\u00CB",
+	"Exists":                   "\u2203",
+	"ExponentialE":             "\u2147",
+	"Fcy":                      "\u0424",
+	"Ffr":                      "\U0001D509",
+	"FilledSmallSquare":        "\u25FC",
+	"FilledVerySmallSquare":    "\u25AA",
+	"Fopf":                     "\U0001D53D",
+	"ForAll":                   "\u2200",
+	"Fouriertrf":               "\u2131",
+	"Fscr":                     "\u2131",
+	"GJcy":                     "\u0403",
+	"GT":                       "\u003E",
+	"Gamma":                    "\u0393",
+	"Gammad":                   "\u03DC",
+	"Gbreve":                   "\u011E",
+	"Gcedil":                   "\u0122",
+	"Gcirc":                    "\u011C",
+	"Gcy":                      "\u0413",
+	"Gdot":                     "\u0120",
+	"Gfr":                      "\U0001D50A",
+	"Gg":                       "\u22D9",
+	"Gopf":                     "\U0001D53E",
+	"GreaterEqual":             "\u2265",
+	"GreaterEqualLess":         "\u22DB",
+	"GreaterFullEqual":         "\u2267",
+	"GreaterGreater":           "\u2AA2",
+	"GreaterLess":              "\u2277",
+	"GreaterSlantEqual":        "\u2A7E",
+	"GreaterTilde":             "\u2273",
+	"Gscr":                     "\U0001D4A2",
+	"Gt":                       "\u226B",
+	"HARDcy":                   "\u042A",
+	"Hacek":                    "\u02C7",
+	"Hat":                      "\u005E",
+	"Hcirc":                    "\u0124",
+	"Hfr":                      "\u210C",
+	"HilbertSpace":             "\u210B",
+	"Hopf":                     "\u210D",
+	"HorizontalLine":           "\u2500",
+	"Hscr":                     "\u210B",
+	"Hstrok":                   "\u0126",
+	"HumpDownHump":             "\u224E",
+	"HumpEqual":                "\u224F",
+	"IEcy":                     "\u0415",
+	"IJlig":                    "\u0132",
+	"IOcy":                     "\u0401",
+	"Iacute":                   "\u00CD",
+	"Icirc":                    "\u00CE",
+	"Icy":                      "\u0418",
+	"Idot":                     "\u0130",
+	"Ifr":                      "\u2111",
+	"Igrave":                   "\u00CC",
+	"Im":                       "\u2111",
+	"Imacr":                    "\u012A",
+	"ImaginaryI":               "\u2148",
+	"Implies":                  "\u21D2",
+	"Int":                      "\u222C",
+	"Integral":                 "\u222B",
+	"Intersection":             "\u22C2",
+	"InvisibleComma":           "\u2063",
+	"InvisibleTimes":           "\u2062",
+	"Iogon":                    "\u012E",
+	"Iopf":                     "\U0001D540",
+	"Iota":                     "\u0399",
+	"Iscr":                     "\u2110",
+	"Itilde":                   "\u0128",
+	"Iukcy":                    "\u0406",
+	"Iuml":                     "\u00CF",
+	"Jcirc":                    "\u0134",
+	"Jcy":                      "\u0419",
+	"Jfr":                      "\U0001D50D",
+	"Jopf":                     "\U0001D541",
+	"Jscr":                     "\U0001D4A5",
+	"Jsercy":                   "\u0408",
+	"Jukcy":                    "\u0404",
+	"KHcy":                     "\u0425",
+	"KJcy":                     "\u040C",
+	"Kappa":                    "\u039A",
+	"Kcedil":                   "\u0136",
+	"Kcy":                      "\u041A",
+	"Kfr":                      "\U0001D50E",
+	"Kopf":                     "\U0001D542",
+	"Kscr":                     "\U0001D4A6",
+	"LJcy":                     "\u0409",
+	"LT":                       "\u003C",
+	"Lacute":                   "\u0139",
+	"Lambda":                   "\u039B",
+	"Lang":                     "\u27EA",
+	"Laplacetrf":               "\u2112",
+	"Larr":                     "\u219E",
+	"Lcaron":                   "\u013D",
+	"Lcedil":                   "\u013B",
+	"Lcy":                      "\u041B",
+	"LeftAngleBracket":         "\u27E8",
+	"LeftArrow":                "\u2190",
+	"LeftArrowBar":             "\u21E4",
+	"LeftArrowRightArrow":      "\u21C6",
+	"LeftCeiling":              "\u2308",
+	"LeftDoubleBracket":        "\u27E6",
+	"LeftDownTeeVector":        "\u2961",
+	"LeftDownVector":           "\u21C3",
+	"LeftDownVectorBar":        "\u2959",
+	"LeftFloor":                "\u230A",
+	"LeftRightArrow":           "\u2194",
+	"LeftRightVector":          "\u294E",
+	"LeftTee":                  "\u22A3",
+	"LeftTeeArrow":             "\u21A4",
+	"LeftTeeVector":            "\u295A",
+	"LeftTriangle":             "\u22B2",
+	"LeftTriangleBar":          "\u29CF",
+	"LeftTriangleEqual":        "\u22B4",
+	"LeftUpDownVector":         "\u2951",
+	"LeftUpTeeVector":          "\u2960",
+	"LeftUpVector":             "\u21BF",
+	"LeftUpVectorBar":          "\u2958",
+	"LeftVector":               "\u21BC",
+	"LeftVectorBar":            "\u2952",
+	"Leftarrow":                "\u21D0",
+	"Leftrightarrow":           "\u21D4",
+	"LessEqualGreater":         "\u22DA",
+	"LessFullEqual":            "\u2266",
+	"LessGreater":              "\u2276",
+	"LessLess":                 "\u2AA1",
+	"LessSlantEqual":           "\u2A7D",
+	"LessTilde":                "\u2272",
+	"Lfr":                      "\U0001D50F",
+	"Ll":                       "\u22D8",
+	"Lleftarrow":               "\u21DA",
+	"Lmidot":                   "\u013F",
+	"LongLeftArrow":            "\u27F5",
+	"LongLeftRightArrow":       "\u27F7",
+	"LongRightArrow":           "\u27F6",
+	"Longleftarrow":            "\u27F8",
+	"Longleftrightarrow":       "\u27FA",
+	"Longrightarrow":           "\u27F9",
+	"Lopf":                     "\U0001D543",
+	"LowerLeftArrow":           "\u2199",
+	"LowerRightArrow":          "\u2198",
+	"Lscr":                     "\u2112",
+	"Lsh":                      "\u21B0",
+	"Lstrok":                   "\u0141",
+	"Lt":                       "\u226A",
+	"Map":                      "\u2905",
+	"Mcy":                      "\u041C",
+	"MediumSpace":              "\u205F",
+	"Mellintrf":                "\u2133",
+	"Mfr":                      "\U0001D510",
+	"MinusPlus":                "\u2213",
+	"Mopf":                     "\U0001D544",
+	"Mscr":                     "\u2133",
+	"Mu":                       "\u039C",
+	"NJcy":                     "\u040A",
+	"Nacute":                   "\u0143",
+	"Ncaron":                   "\u0147",
+	"Ncedil":                   "\u0145",
+	"Ncy":                      "\u041D",
+	"NegativeMediumSpace":     "\u200B",
+	"NegativeThickSpace":      "\u200B",
+	"NegativeThinSpace":       "\u200B",
+	"NegativeVeryThinSpace":   "\u200B",
+	"NestedGreaterGreater":    "\u226B",
+	"NestedLessLess":          "\u226A",
+	"NewLine":                 "\u000A",
+	"Nfr":                     "\U0001D511",
+	"NoBreak":                 "\u2060",
+	"NonBreakingSpace":        "\u00A0",
+	"Nopf":                    "\u2115",
+	"Not":                     "\u2AEC",
+	"NotCongruent":            "\u2262",
+	"NotCupCap":               "\u226D",
+	"NotDoubleVerticalBar":    "\u2226",
+	"NotElement":              "\u2209",
+	"NotEqual":                "\u2260",
+	"NotEqualTilde":           "\u2242\u0338",
+	"NotExists":               "\u2204",
+	"NotGreater":              "\u226F",
+	"NotGreaterEqual":         "\u2271",
+	"NotGreaterFullEqual":     "\u2267\u0338",
+	"NotGreaterGreater":       "\u226B\u0338",
+	"NotGreaterLess":          "\u2279",
+	"NotGreaterSlantEqual":    "\u2A7E\u0338",
+	"NotGreaterTilde":         "\u2275",
+	"NotHumpDownHump":         "\u224E\u0338",
+	"NotHumpEqual":            "\u224F\u0338",
+	"NotLeftTriangle":         "\u22EA",
+	"NotLeftTriangleBar":      "\u29CF\u0338",
+	"NotLeftTriangleEqual":    "\u22EC",
+	"NotLess":                 "\u226E",
+	"NotLessEqual":            "\u2270",
+	"NotLessGreater":          "\u2278",
+	"NotLessLess":             "\u226A\u0338",
+	"NotLessSlantEqual":       "\u2A7D\u0338",
+	"NotLessTilde":            "\u2274",
+	"NotNestedGreaterGreater": "\u2AA2\u0338",
+	"NotNestedLessLess":       "\u2AA1\u0338",
+	"NotPrecedes":             "\u2280",
+	"NotPrecedesEqual":        "\u2AAF\u0338",
+	"NotPrecedesSlantEqual":   "\u22E0",
+	"NotReverseElement":       "\u220C",
+	"NotRightTriangle":        "\u22EB",
+	"NotRightTriangleBar":     "\u29D0\u0338",
+	"NotRightTriangleEqual":   "\u22ED",
+	"NotSquareSubset":         "\u228F\u0338",
+	"NotSquareSubsetEqual":    "\u22E2",
+	"NotSquareSuperset":       "\u2290\u0338",
+	"NotSquareSupersetEqual":  "\u22E3",
+	"NotSubset":               "\u2282\u20D2",
+	"NotSubsetEqual":          "\u2288",
+	"NotSucceeds":             "\u2281",
+	"NotSucceedsEqual":        "\u2AB0\u0338",
+	"NotSucceedsSlantEqual":   "\u22E1",
+	"NotSucceedsTilde":        "\u227F\u0338",
+	"NotSuperset":             "\u2283\u20D2",
+	"NotSupersetEqual":        "\u2289",
+	"NotTilde":                "\u2241",
+	"NotTildeEqual":           "\u2244",
+	"NotTildeFullEqual":       "\u2247",
+	"NotTildeTilde":           "\u2249",
+	"NotVerticalBar":          "\u2224",
+	"Nscr":                    "\U0001D4A9",
+	"Ntilde":                  "\u00D1",
+	"Nu":                      "\u039D",
+	"OElig":                   "\u0152",
+	"Oacute":                  "\u00D3",
+	"Ocirc":                   "\u00D4",
+	"Ocy":                     "\u041E",
+	"Odblac":                  "\u0150",
+	"Ofr":                     "\U0001D512",
+	"Ograve":                  "\u00D2",
+	"Omacr":                   "\u014C",
+	"Omega":                   "\u03A9",
+	"Omicron":                 "\u039F",
+	"Oopf":                    "\U0001D546",
+	"OpenCurlyDoubleQuote":    "\u201C",
+	"OpenCurlyQuote":          "\u2018",
+	"Or":                      "\u2A54",
+	"Oscr":                    "\U0001D4AA",
+	"Oslash":                  "\u00D8",
+	"Otilde":                  "\u00D5",
+	"Otimes":                  "\u2A37",
+	"Ouml":                    "\u00D6",
+	"OverBar":                 "\u203E",
+	"OverBrace":               "\u23DE",
+	"OverBracket":             "\u23B4",
+	"OverParenthesis":         "\u23DC",
+	"PartialD":                "\u2202",
+	"Pcy":                     "\u041F",
+	"Pfr":                     "\U0001D513",
+	"Phi":                     "\u03A6",
+	"Pi":                      "\u03A0",
+	"PlusMinus":               "\u00B1",
+	"Poincareplane":           "\u210C",
+	"Popf":                    "\u2119",
+	"Pr":                      "\u2ABB",
+	"Precedes":                "\u227A",
+	"PrecedesEqual":           "\u2AAF",
+	"PrecedesSlantEqual":      "\u227C",
+	"PrecedesTilde":           "\u227E",
+	"Prime":                   "\u2033",
+	"Product":                 "\u220F",
+	"Proportion":              "\u2237",
+	"Proportional":            "\u221D",
+	"Pscr":                    "\U0001D4AB",
+	"Psi":                     "\u03A8",
+	"QUOT":                    "\u0022",
+	"Qfr":                     "\U0001D514",
+	"Qopf":                    "\u211A",
+	"Qscr":                    "\U0001D4AC",
+	"RBarr":                   "\u2910",
+	"REG":                     "\u00AE",
+	"Racute":                  "\u0154",
+	"Rang":                    "\u27EB",
+	"Rarr":                    "\u21A0",
+	"Rarrtl":                  "\u2916",
+	"Rcaron":                  "\u0158",
+	"Rcedil":                  "\u0156",
+	"Rcy":                     "\u0420",
+	"Re":                      "\u211C",
+	"ReverseElement":          "\u220B",
+	"ReverseEquilibrium":      "\u21CB",
+	"ReverseUpEquilibrium":    "\u296F",
+	"Rfr":                 "\u211C",
+	"Rho":                 "\u03A1",
+	"RightAngleBracket":   "\u27E9",
+	"RightArrow":          "\u2192",
+	"RightArrowBar":       "\u21E5",
+	"RightArrowLeftArrow": "\u21C4",
+	"RightCeiling":        "\u2309",
+	"RightDoubleBracket":  "\u27E7",
+	"RightDownTeeVector":  "\u295D",
+	"RightDownVector":     "\u21C2",
+	"RightDownVectorBar":  "\u2955",
+	"RightFloor":          "\u230B",
+	"RightTee":            "\u22A2",
+	"RightTeeArrow":       "\u21A6",
+	"RightTeeVector":      "\u295B",
+	"RightTriangle":       "\u22B3",
+	"RightTriangleBar":    "\u29D0",
+	"RightTriangleEqual":  "\u22B5",
+	"RightUpDownVector":   "\u294F",
+	"RightUpTeeVector":    "\u295C",
+	"RightUpVector":       "\u21BE",
+	"RightUpVectorBar":    "\u2954",
+	"RightVector":         "\u21C0",
+	"RightVectorBar":      "\u2953",
+	"Rightarrow":          "\u21D2",
+	"Ropf":                "\u211D",
+	"RoundImplies":        "\u2970",
+	"Rrightarrow":         "\u21DB",
+	"Rscr":                "\u211B",
+	"Rsh":                 "\u21B1",
+	"RuleDelayed":         "\u29F4",
+	"SHCHcy":              "\u0429",
+	"SHcy":                "\u0428",
+	"SOFTcy":              "\u042C",
+	"Sacute":              "\u015A",
+	"Sc":                  "\u2ABC",
+	"Scaron":              "\u0160",
+	"Scedil":              "\u015E",
+	"Scirc":               "\u015C",
+	"Scy":                 "\u0421",
+	"Sfr":                 "\U0001D516",
+	"ShortDownArrow":      "\u2193",
+	"ShortLeftArrow":      "\u2190",
+	"ShortRightArrow":     "\u2192",
+	"ShortUpArrow":        "\u2191",
+	"Sigma":               "\u03A3",
+	"SmallCircle":         "\u2218",
+	"Sopf":                "\U0001D54A",
+	"Sqrt":                "\u221A",
+	"Square":              "\u25A1",
+	"SquareIntersection":  "\u2293",
+	"SquareSubset":        "\u228F",
+	"SquareSubsetEqual":   "\u2291",
+	"SquareSuperset":      "\u2290",
+	"SquareSupersetEqual": "\u2292",
+	"SquareUnion":         "\u2294",
+	"Sscr":                "\U0001D4AE",
+	"Star":                "\u22C6",
+	"Sub":                 "\u22D0",
+	"Subset":              "\u22D0",
+	"SubsetEqual":         "\u2286",
+	"Succeeds":            "\u227B",
+	"SucceedsEqual":       "\u2AB0",
+	"SucceedsSlantEqual":  "\u227D",
+	"SucceedsTilde":       "\u227F",
+	"SuchThat":            "\u220B",
+	"Sum":                 "\u2211",
+	"Sup":                 "\u22D1",
+	"Superset":            "\u2283",
+	"SupersetEqual":       "\u2287",
+	"Supset":              "\u22D1",
+	"THORN":               "\u00DE",
+	"TRADE":               "\u2122",
+	"TSHcy":               "\u040B",
+	"TScy":                "\u0426",
+	"Tab":                 "\u0009",
+	"Tau":                 "\u03A4",
+	"Tcaron":              "\u0164",
+	"Tcedil":              "\u0162",
+	"Tcy":                 "\u0422",
+	"Tfr":                 "\U0001D517",
+	"Therefore":           "\u2234",
+	"Theta":               "\u0398",
+	"ThickSpace":          "\u205F\u200A",
+	"ThinSpace":           "\u2009",
+	"Tilde":               "\u223C",
+	"TildeEqual":          "\u2243",
+	"TildeFullEqual":      "\u2245",
+	"TildeTilde":          "\u2248",
+	"Topf":                "\U0001D54B",
+	"TripleDot":           "\u20DB",
+	"Tscr":                "\U0001D4AF",
+	"Tstrok":              "\u0166",
+	"Uacute":              "\u00DA",
+	"Uarr":                "\u219F",
+	"Uarrocir":            "\u2949",
+	"Ubrcy":               "\u040E",
+	"Ubreve":              "\u016C",
+	"Ucirc":               "\u00DB",
+	"Ucy":                 "\u0423",
+	"Udblac":              "\u0170",
+	"Ufr":                 "\U0001D518",
+	"Ugrave":              "\u00D9",
+	"Umacr":               "\u016A",
+	"UnderBar":            "\u005F",
+	"UnderBrace":          "\u23DF",
+	"UnderBracket":        "\u23B5",
+	"UnderParenthesis":    "\u23DD",
+	"Union":               "\u22C3",
+	"UnionPlus":           "\u228E",
+	"Uogon":               "\u0172",
+	"Uopf":                "\U0001D54C",
+	"UpArrow":             "\u2191",
+	"UpArrowBar":          "\u2912",
+	"UpArrowDownArrow":    "\u21C5",
+	"UpDownArrow":         "\u2195",
+	"UpEquilibrium":       "\u296E",
+	"UpTee":               "\u22A5",
+	"UpTeeArrow":          "\u21A5",
+	"Uparrow":             "\u21D1",
+	"Updownarrow":         "\u21D5",
+	"UpperLeftArrow":      "\u2196",
+	"UpperRightArrow":     "\u2197",
+	"Upsi":                "\u03D2",
+	"Upsilon":             "\u03A5",
+	"Uring":               "\u016E",
+	"Uscr":                "\U0001D4B0",
+	"Utilde":              "\u0168",
+	"Uuml":                "\u00DC",
+	"VDash":               "\u22AB",
+	"Vbar":                "\u2AEB",
+	"Vcy":                 "\u0412",
+	"Vdash":               "\u22A9",
+	"Vdashl":              "\u2AE6",
+	"Vee":                 "\u22C1",
+	"Verbar":              "\u2016",
+	"Vert":                "\u2016",
+	"VerticalBar":         "\u2223",
+	"VerticalLine":        "\u007C",
+	"VerticalSeparator":   "\u2758",
+	"VerticalTilde":       "\u2240",
+	"VeryThinSpace":       "\u200A",
+	"Vfr":                 "\U0001D519",
+	"Vopf":                "\U0001D54D",
+	"Vscr":                "\U0001D4B1",
+	"Vvdash":              "\u22AA",
+	"Wcirc":               "\u0174",
+	"Wedge":               "\u22C0",
+	"Wfr":                 "\U0001D51A",
+	"Wopf":                "\U0001D54E",
+	"Wscr":                "\U0001D4B2",
+	"Xfr":                 "\U0001D51B",
+	"Xi":                  "\u039E",
+	"Xopf":                "\U0001D54F",
+	"Xscr":                "\U0001D4B3",
+	"YAcy":                "\u042F",
+	"YIcy":                "\u0407",
+	"YUcy":                "\u042E",
+	"Yacute":              "\u00DD",
+	"Ycirc":               "\u0176",
+	"Ycy":                 "\u042B",
+	"Yfr":                 "\U0001D51C",
+	"Yopf":                "\U0001D550",
+	"Yscr":                "\U0001D4B4",
+	"Yuml":                "\u0178",
+	"ZHcy":                "\u0416",
+	"Zacute":              "\u0179",
+	"Zcaron":              "\u017D",
+	"Zcy":                 "\u0417",
+	"Zdot":                "\u017B",
+	"ZeroWidthSpace":      "\u200B",
+	"Zeta":                "\u0396",
+	"Zfr":                 "\u2128",
+	"Zopf":                "\u2124",
+	"Zscr":                "\U0001D4B5",
+	"aacute":              "\u00E1",
+	"abreve":              "\u0103",
+	"ac":                  "\u223E",
+	"acE":                 "\u223E\u0333",
+	"acd":                 "\u223F",
+	"acirc":               "\u00E2",
+	"acute":               "\u00B4",
+	"acy":                 "\u0430",
+	"aelig":               "\u00E6",
+	"af":                  "\u2061",
+	"afr":                 "\U0001D51E",
+	"agrave":              "\u00E0",
+	"alefsym":             "\u2135",
+	"aleph":               "\u2135",
+	"alpha":               "\u03B1",
+	"amacr":               "\u0101",
+	"amalg":               "\u2A3F",
+	"amp":                 "\u0026",
+	"and":                 "\u2227",
+	"andand":              "\u2A55",
+	"andd":                "\u2A5C",
+	"andslope":            "\u2A58",
+	"andv":                "\u2A5A",
+	"ang":                 "\u2220",
+	"ange":                "\u29A4",
+	"angle":               "\u2220",
+	"angmsd":              "\u2221",
+	"angmsdaa":            "\u29A8",
+	"angmsdab":            "\u29A9",
+	"angmsdac":            "\u29AA",
+	"angmsdad":            "\u29AB",
+	"angmsdae":            "\u29AC",
+	"angmsdaf":            "\u29AD",
+	"angmsdag":            "\u29AE",
+	"angmsdah":            "\u29AF",
+	"angrt":               "\u221F",
+	"angrtvb":             "\u22BE",
+	"angrtvbd":            "\u299D",
+	"angsph":              "\u2222",
+	"angst":               "\u00C5",
+	"angzarr":             "\u237C",
+	"aogon":               "\u0105",
+	"aopf":                "\U0001D552",
+	"ap":                  "\u2248",
+	"apE":                 "\u2A70",
+	"apacir":              "\u2A6F",
+	"ape":                 "\u224A",
+	"apid":                "\u224B",
+	"apos":                "\u0027",
+	"approx":              "\u2248",
+	"approxeq":            "\u224A",
+	"aring":               "\u00E5",
+	"ascr":                "\U0001D4B6",
+	"ast":                 "\u002A",
+	"asymp":               "\u2248",
+	"asympeq":             "\u224D",
+	"atilde":              "\u00E3",
+	"auml":                "\u00E4",
+	"awconint":            "\u2233",
+	"awint":               "\u2A11",
+	"bNot":                "\u2AED",
+	"backcong":            "\u224C",
+	"backepsilon":         "\u03F6",
+	"backprime":           "\u2035",
+	"backsim":             "\u223D",
+	"backsimeq":           "\u22CD",
+	"barvee":              "\u22BD",
+	"barwed":              "\u2305",
+	"barwedge":            "\u2305",
+	"bbrk":                "\u23B5",
+	"bbrktbrk":            "\u23B6",
+	"bcong":               "\u224C",
+	"bcy":                 "\u0431",
+	"bdquo":               "\u201E",
+	"becaus":              "\u2235",
+	"because":             "\u2235",
+	"bemptyv":             "\u29B0",
+	"bepsi":               "\u03F6",
+	"bernou":              "\u212C",
+	"beta":                "\u03B2",
+	"beth":                "\u2136",
+	"between":             "\u226C",
+	"bfr":                 "\U0001D51F",
+	"bigcap":              "\u22C2",
+	"bigcirc":             "\u25EF",
+	"bigcup":              "\u22C3",
+	"bigodot":             "\u2A00",
+	"bigoplus":            "\u2A01",
+	"bigotimes":           "\u2A02",
+	"bigsqcup":            "\u2A06",
+	"bigstar":             "\u2605",
+	"bigtriangledown":     "\u25BD",
+	"bigtriangleup":       "\u25B3",
+	"biguplus":            "\u2A04",
+	"bigvee":              "\u22C1",
+	"bigwedge":            "\u22C0",
+	"bkarow":              "\u290D",
+	"blacklozenge":        "\u29EB",
+	"blacksquare":         "\u25AA",
+	"blacktriangle":       "\u25B4",
+	"blacktriangledown":   "\u25BE",
+	"blacktriangleleft":   "\u25C2",
+	"blacktriangleright":  "\u25B8",
+	"blank":               "\u2423",
+	"blk12":               "\u2592",
+	"blk14":               "\u2591",
+	"blk34":               "\u2593",
+	"block":               "\u2588",
+	"bne":                 "\u003D\u20E5",
+	"bnequiv":             "\u2261\u20E5",
+	"bnot":                "\u2310",
+	"bopf":                "\U0001D553",
+	"bot":                 "\u22A5",
+	"bottom":              "\u22A5",
+	"bowtie":              "\u22C8",
+	"boxDL":               "\u2557",
+	"boxDR":               "\u2554",
+	"boxDl":               "\u2556",
+	"boxDr":               "\u2553",
+	"boxH":                "\u2550",
+	"boxHD":               "\u2566",
+	"boxHU":               "\u2569",
+	"boxHd":               "\u2564",
+	"boxHu":               "\u2567",
+	"boxUL":               "\u255D",
+	"boxUR":               "\u255A",
+	"boxUl":               "\u255C",
+	"boxUr":               "\u2559",
+	"boxV":                "\u2551",
+	"boxVH":               "\u256C",
+	"boxVL":               "\u2563",
+	"boxVR":               "\u2560",
+	"boxVh":               "\u256B",
+	"boxVl":               "\u2562",
+	"boxVr":               "\u255F",
+	"boxbox":              "\u29C9",
+	"boxdL":               "\u2555",
+	"boxdR":               "\u2552",
+	"boxdl":               "\u2510",
+	"boxdr":               "\u250C",
+	"boxh":                "\u2500",
+	"boxhD":               "\u2565",
+	"boxhU":               "\u2568",
+	"boxhd":               "\u252C",
+	"boxhu":               "\u2534",
+	"boxminus":            "\u229F",
+	"boxplus":             "\u229E",
+	"boxtimes":            "\u22A0",
+	"boxuL":               "\u255B",
+	"boxuR":               "\u2558",
+	"boxul":               "\u2518",
+	"boxur":               "\u2514",
+	"boxv":                "\u2502",
+	"boxvH":               "\u256A",
+	"boxvL":               "\u2561",
+	"boxvR":               "\u255E",
+	"boxvh":               "\u253C",
+	"boxvl":               "\u2524",
+	"boxvr":               "\u251C",
+	"bprime":              "\u2035",
+	"breve":               "\u02D8",
+	"brvbar":              "\u00A6",
+	"bscr":                "\U0001D4B7",
+	"bsemi":               "\u204F",
+	"bsim":                "\u223D",
+	"bsime":               "\u22CD",
+	"bsol":                "\u005C",
+	"bsolb":               "\u29C5",
+	"bsolhsub":            "\u27C8",
+	"bull":                "\u2022",
+	"bullet":              "\u2022",
+	"bump":                "\u224E",
+	"bumpE":               "\u2AAE",
+	"bumpe":               "\u224F",
+	"bumpeq":              "\u224F",
+	"cacute":              "\u0107",
+	"cap":                 "\u2229",
+	"capand":              "\u2A44",
+	"capbrcup":            "\u2A49",
+	"capcap":              "\u2A4B",
+	"capcup":              "\u2A47",
+	"capdot":              "\u2A40",
+	"caps":                "\u2229\uFE00",
+	"caret":               "\u2041",
+	"caron":               "\u02C7",
+	"ccaps":               "\u2A4D",
+	"ccaron":              "\u010D",
+	"ccedil":              "\u00E7",
+	"ccirc":               "\u0109",
+	"ccups":               "\u2A4C",
+	"ccupssm":             "\u2A50",
+	"cdot":                "\u010B",
+	"cedil":               "\u00B8",
+	"cemptyv":             "\u29B2",
+	"cent":                "\u00A2",
+	"centerdot":           "\u00B7",
+	"cfr":                 "\U0001D520",
+	"chcy":                "\u0447",
+	"check":               "\u2713",
+	"checkmark":           "\u2713",
+	"chi":                 "\u03C7",
+	"cir":                 "\u25CB",
+	"cirE":                "\u29C3",
+	"circ":                "\u02C6",
+	"circeq":              "\u2257",
+	"circlearrowleft":     "\u21BA",
+	"circlearrowright":    "\u21BB",
+	"circledR":            "\u00AE",
+	"circledS":            "\u24C8",
+	"circledast":          "\u229B",
+	"circledcirc":         "\u229A",
+	"circleddash":         "\u229D",
+	"cire":                "\u2257",
+	"cirfnint":            "\u2A10",
+	"cirmid":              "\u2AEF",
+	"cirscir":             "\u29C2",
+	"clubs":               "\u2663",
+	"clubsuit":            "\u2663",
+	"colon":               "\u003A",
+	"colone":              "\u2254",
+	"coloneq":             "\u2254",
+	"comma":               "\u002C",
+	"commat":              "\u0040",
+	"comp":                "\u2201",
+	"compfn":              "\u2218",
+	"complement":          "\u2201",
+	"complexes":           "\u2102",
+	"cong":                "\u2245",
+	"congdot":             "\u2A6D",
+	"conint":              "\u222E",
+	"copf":                "\U0001D554",
+	"coprod":              "\u2210",
+	"copy":                "\u00A9",
+	"copysr":              "\u2117",
+	"crarr":               "\u21B5",
+	"cross":               "\u2717",
+	"cscr":                "\U0001D4B8",
+	"csub":                "\u2ACF",
+	"csube":               "\u2AD1",
+	"csup":                "\u2AD0",
+	"csupe":               "\u2AD2",
+	"ctdot":               "\u22EF",
+	"cudarrl":             "\u2938",
+	"cudarrr":             "\u2935",
+	"cuepr":               "\u22DE",
+	"cuesc":               "\u22DF",
+	"cularr":              "\u21B6",
+	"cularrp":             "\u293D",
+	"cup":                 "\u222A",
+	"cupbrcap":            "\u2A48",
+	"cupcap":              "\u2A46",
+	"cupcup":              "\u2A4A",
+	"cupdot":              "\u228D",
+	"cupor":               "\u2A45",
+	"cups":                "\u222A\uFE00",
+	"curarr":              "\u21B7",
+	"curarrm":             "\u293C",
+	"curlyeqprec":         "\u22DE",
+	"curlyeqsucc":         "\u22DF",
+	"curlyvee":            "\u22CE",
+	"curlywedge":          "\u22CF",
+	"curren":              "\u00A4",
+	"curvearrowleft":      "\u21B6",
+	"curvearrowright":     "\u21B7",
+	"cuvee":               "\u22CE",
+	"cuwed":               "\u22CF",
+	"cwconint":            "\u2232",
+	"cwint":               "\u2231",
+	"cylcty":              "\u232D",
+	"dArr":                "\u21D3",
+	"dHar":                "\u2965",
+	"dagger":              "\u2020",
+	"daleth":              "\u2138",
+	"darr":                "\u2193",
+	"dash":                "\u2010",
+	"dashv":               "\u22A3",
+	"dbkarow":             "\u290F",
+	"dblac":               "\u02DD",
+	"dcaron":              "\u010F",
+	"dcy":                 "\u0434",
+	"dd":                  "\u2146",
+	"ddagger":             "\u2021",
+	"ddarr":               "\u21CA",
+	"ddotseq":             "\u2A77",
+	"deg":                 "\u00B0",
+	"delta":               "\u03B4",
+	"demptyv":             "\u29B1",
+	"dfisht":              "\u297F",
+	"dfr":                 "\U0001D521",
+	"dharl":               "\u21C3",
+	"dharr":               "\u21C2",
+	"diam":                "\u22C4",
+	"diamond":             "\u22C4",
+	"diamondsuit":         "\u2666",
+	"diams":               "\u2666",
+	"die":                 "\u00A8",
+	"digamma":             "\u03DD",
+	"disin":               "\u22F2",
+	"div":                 "\u00F7",
+	"divide":              "\u00F7",
+	"divideontimes":       "\u22C7",
+	"divonx":              "\u22C7",
+	"djcy":                "\u0452",
+	"dlcorn":              "\u231E",
+	"dlcrop":              "\u230D",
+	"dollar":              "\u0024",
+	"dopf":                "\U0001D555",
+	"dot":                 "\u02D9",
+	"doteq":               "\u2250",
+	"doteqdot":            "\u2251",
+	"dotminus":            "\u2238",
+	"dotplus":             "\u2214",
+	"dotsquare":           "\u22A1",
+	"doublebarwedge":      "\u2306",
+	"downarrow":           "\u2193",
+	"downdownarrows":      "\u21CA",
+	"downharpoonleft":     "\u21C3",
+	"downharpoonright":    "\u21C2",
+	"drbkarow":            "\u2910",
+	"drcorn":              "\u231F",
+	"drcrop":              "\u230C",
+	"dscr":                "\U0001D4B9",
+	"dscy":                "\u0455",
+	"dsol":                "\u29F6",
+	"dstrok":              "\u0111",
+	"dtdot":               "\u22F1",
+	"dtri":                "\u25BF",
+	"dtrif":               "\u25BE",
+	"duarr":               "\u21F5",
+	"duhar":               "\u296F",
+	"dwangle":             "\u29A6",
+	"dzcy":                "\u045F",
+	"dzigrarr":            "\u27FF",
+	"eDDot":               "\u2A77",
+	"eDot":                "\u2251",
+	"eacute":              "\u00E9",
+	"easter":              "\u2A6E",
+	"ecaron":              "\u011B",
+	"ecir":                "\u2256",
+	"ecirc":               "\u00EA",
+	"ecolon":              "\u2255",
+	"ecy":                 "\u044D",
+	"edot":                "\u0117",
+	"ee":                  "\u2147",
+	"efDot":               "\u2252",
+	"efr":                 "\U0001D522",
+	"eg":                  "\u2A9A",
+	"egrave":              "\u00E8",
+	"egs":                 "\u2A96",
+	"egsdot":              "\u2A98",
+	"el":                  "\u2A99",
+	"elinters":            "\u23E7",
+	"ell":                 "\u2113",
+	"els":                 "\u2A95",
+	"elsdot":              "\u2A97",
+	"emacr":               "\u0113",
+	"empty":               "\u2205",
+	"emptyset":            "\u2205",
+	"emptyv":              "\u2205",
+	"emsp":                "\u2003",
+	"emsp13":              "\u2004",
+	"emsp14":              "\u2005",
+	"eng":                 "\u014B",
+	"ensp":                "\u2002",
+	"eogon":               "\u0119",
+	"eopf":                "\U0001D556",
+	"epar":                "\u22D5",
+	"eparsl":              "\u29E3",
+	"eplus":               "\u2A71",
+	"epsi":                "\u03B5",
+	"epsilon":             "\u03B5",
+	"epsiv":               "\u03F5",
+	"eqcirc":              "\u2256",
+	"eqcolon":             "\u2255",
+	"eqsim":               "\u2242",
+	"eqslantgtr":          "\u2A96",
+	"eqslantless":         "\u2A95",
+	"equals":              "\u003D",
+	"equest":              "\u225F",
+	"equiv":               "\u2261",
+	"equivDD":             "\u2A78",
+	"eqvparsl":            "\u29E5",
+	"erDot":               "\u2253",
+	"erarr":               "\u2971",
+	"escr":                "\u212F",
+	"esdot":               "\u2250",
+	"esim":                "\u2242",
+	"eta":                 "\u03B7",
+	"eth":                 "\u00F0",
+	"euml":                "\u00EB",
+	"euro":                "\u20AC",
+	"excl":                "\u0021",
+	"exist":               "\u2203",
+	"expectation":         "\u2130",
+	"exponentiale":        "\u2147",
+	"fallingdotseq":       "\u2252",
+	"fcy":                 "\u0444",
+	"female":              "\u2640",
+	"ffilig":              "\uFB03",
+	"fflig":               "\uFB00",
+	"ffllig":              "\uFB04",
+	"ffr":                 "\U0001D523",
+	"filig":               "\uFB01",
+	"fjlig":               "\u0066\u006A",
+	"flat":                "\u266D",
+	"fllig":               "\uFB02",
+	"fltns":               "\u25B1",
+	"fnof":                "\u0192",
+	"fopf":                "\U0001D557",
+	"forall":              "\u2200",
+	"fork":                "\u22D4",
+	"forkv":               "\u2AD9",
+	"fpartint":            "\u2A0D",
+	"frac12":              "\u00BD",
+	"frac13":              "\u2153",
+	"frac14":              "\u00BC",
+	"frac15":              "\u2155",
+	"frac16":              "\u2159",
+	"frac18":              "\u215B",
+	"frac23":              "\u2154",
+	"frac25":              "\u2156",
+	"frac34":              "\u00BE",
+	"frac35":              "\u2157",
+	"frac38":              "\u215C",
+	"frac45":              "\u2158",
+	"frac56":              "\u215A",
+	"frac58":              "\u215D",
+	"frac78":              "\u215E",
+	"frasl":               "\u2044",
+	"frown":               "\u2322",
+	"fscr":                "\U0001D4BB",
+	"gE":                  "\u2267",
+	"gEl":                 "\u2A8C",
+	"gacute":              "\u01F5",
+	"gamma":               "\u03B3",
+	"gammad":              "\u03DD",
+	"gap":                 "\u2A86",
+	"gbreve":              "\u011F",
+	"gcirc":               "\u011D",
+	"gcy":                 "\u0433",
+	"gdot":                "\u0121",
+	"ge":                  "\u2265",
+	"gel":                 "\u22DB",
+	"geq":                 "\u2265",
+	"geqq":                "\u2267",
+	"geqslant":            "\u2A7E",
+	"ges":                 "\u2A7E",
+	"gescc":               "\u2AA9",
+	"gesdot":              "\u2A80",
+	"gesdoto":             "\u2A82",
+	"gesdotol":            "\u2A84",
+	"gesl":                "\u22DB\uFE00",
+	"gesles":              "\u2A94",
+	"gfr":                 "\U0001D524",
+	"gg":                  "\u226B",
+	"ggg":                 "\u22D9",
+	"gimel":               "\u2137",
+	"gjcy":                "\u0453",
+	"gl":                  "\u2277",
+	"glE":                 "\u2A92",
+	"gla":                 "\u2AA5",
+	"glj":                 "\u2AA4",
+	"gnE":                 "\u2269",
+	"gnap":                "\u2A8A",
+	"gnapprox":            "\u2A8A",
+	"gne":                 "\u2A88",
+	"gneq":                "\u2A88",
+	"gneqq":               "\u2269",
+	"gnsim":               "\u22E7",
+	"gopf":                "\U0001D558",
+	"grave":               "\u0060",
+	"gscr":                "\u210A",
+	"gsim":                "\u2273",
+	"gsime":               "\u2A8E",
+	"gsiml":               "\u2A90",
+	"gt":                  "\u003E",
+	"gtcc":                "\u2AA7",
+	"gtcir":               "\u2A7A",
+	"gtdot":               "\u22D7",
+	"gtlPar":              "\u2995",
+	"gtquest":             "\u2A7C",
+	"gtrapprox":           "\u2A86",
+	"gtrarr":              "\u2978",
+	"gtrdot":              "\u22D7",
+	"gtreqless":           "\u22DB",
+	"gtreqqless":          "\u2A8C",
+	"gtrless":             "\u2277",
+	"gtrsim":              "\u2273",
+	"gvertneqq":           "\u2269\uFE00",
+	"gvnE":                "\u2269\uFE00",
+	"hArr":                "\u21D4",
+	"hairsp":              "\u200A",
+	"half":                "\u00BD",
+	"hamilt":              "\u210B",
+	"hardcy":              "\u044A",
+	"harr":                "\u2194",
+	"harrcir":             "\u2948",
+	"harrw":               "\u21AD",
+	"hbar":                "\u210F",
+	"hcirc":               "\u0125",
+	"hearts":              "\u2665",
+	"heartsuit":           "\u2665",
+	"hellip":              "\u2026",
+	"hercon":              "\u22B9",
+	"hfr":                 "\U0001D525",
+	"hksearow":            "\u2925",
+	"hkswarow":            "\u2926",
+	"hoarr":               "\u21FF",
+	"homtht":              "\u223B",
+	"hookleftarrow":       "\u21A9",
+	"hookrightarrow":      "\u21AA",
+	"hopf":                "\U0001D559",
+	"horbar":              "\u2015",
+	"hscr":                "\U0001D4BD",
+	"hslash":              "\u210F",
+	"hstrok":              "\u0127",
+	"hybull":              "\u2043",
+	"hyphen":              "\u2010",
+	"iacute":              "\u00ED",
+	"ic":                  "\u2063",
+	"icirc":               "\u00EE",
+	"icy":                 "\u0438",
+	"iecy":                "\u0435",
+	"iexcl":               "\u00A1",
+	"iff":                 "\u21D4",
+	"ifr":                 "\U0001D526",
+	"igrave":              "\u00EC",
+	"ii":                  "\u2148",
+	"iiiint":              "\u2A0C",
+	"iiint":               "\u222D",
+	"iinfin":              "\u29DC",
+	"iiota":               "\u2129",
+	"ijlig":               "\u0133",
+	"imacr":               "\u012B",
+	"image":               "\u2111",
+	"imagline":            "\u2110",
+	"imagpart":            "\u2111",
+	"imath":               "\u0131",
+	"imof":                "\u22B7",
+	"imped":               "\u01B5",
+	"in":                  "\u2208",
+	"incare":              "\u2105",
+	"infin":               "\u221E",
+	"infintie":            "\u29DD",
+	"inodot":              "\u0131",
+	"int":                 "\u222B",
+	"intcal":              "\u22BA",
+	"integers":            "\u2124",
+	"intercal":            "\u22BA",
+	"intlarhk":            "\u2A17",
+	"intprod":             "\u2A3C",
+	"iocy":                "\u0451",
+	"iogon":               "\u012F",
+	"iopf":                "\U0001D55A",
+	"iota":                "\u03B9",
+	"iprod":               "\u2A3C",
+	"iquest":              "\u00BF",
+	"iscr":                "\U0001D4BE",
+	"isin":                "\u2208",
+	"isinE":               "\u22F9",
+	"isindot":             "\u22F5",
+	"isins":               "\u22F4",
+	"isinsv":              "\u22F3",
+	"isinv":               "\u2208",
+	"it":                  "\u2062",
+	"itilde":              "\u0129",
+	"iukcy":               "\u0456",
+	"iuml":                "\u00EF",
+	"jcirc":               "\u0135",
+	"jcy":                 "\u0439",
+	"jfr":                 "\U0001D527",
+	"jmath":               "\u0237",
+	"jopf":                "\U0001D55B",
+	"jscr":                "\U0001D4BF",
+	"jsercy":              "\u0458",
+	"jukcy":               "\u0454",
+	"kappa":               "\u03BA",
+	"kappav":              "\u03F0",
+	"kcedil":              "\u0137",
+	"kcy":                 "\u043A",
+	"kfr":                 "\U0001D528",
+	"kgreen":              "\u0138",
+	"khcy":                "\u0445",
+	"kjcy":                "\u045C",
+	"kopf":                "\U0001D55C",
+	"kscr":                "\U0001D4C0",
+	"lAarr":               "\u21DA",
+	"lArr":                "\u21D0",
+	"lAtail":              "\u291B",
+	"lBarr":               "\u290E",
+	"lE":                  "\u2266",
+	"lEg":                 "\u2A8B",
+	"lHar":                "\u2962",
+	"lacute":              "\u013A",
+	"laemptyv":            "\u29B4",
+	"lagran":              "\u2112",
+	"lambda":              "\u03BB",
+	"lang":                "\u27E8",
+	"langd":               "\u2991",
+	"langle":              "\u27E8",
+	"lap":                 "\u2A85",
+	"laquo":               "\u00AB",
+	"larr":                "\u2190",
+	"larrb":               "\u21E4",
+	"larrbfs":             "\u291F",
+	"larrfs":              "\u291D",
+	"larrhk":              "\u21A9",
+	"larrlp":              "\u21AB",
+	"larrpl":              "\u2939",
+	"larrsim":             "\u2973",
+	"larrtl":              "\u21A2",
+	"lat":                 "\u2AAB",
+	"latail":              "\u2919",
+	"late":                "\u2AAD",
+	"lates":               "\u2AAD\uFE00",
+	"lbarr":               "\u290C",
+	"lbbrk":               "\u2772",
+	"lbrace":              "\u007B",
+	"lbrack":              "\u005B",
+	"lbrke":               "\u298B",
+	"lbrksld":             "\u298F",
+	"lbrkslu":             "\u298D",
+	"lcaron":              "\u013E",
+	"lcedil":              "\u013C",
+	"lceil":               "\u2308",
+	"lcub":                "\u007B",
+	"lcy":                 "\u043B",
+	"ldca":                "\u2936",
+	"ldquo":               "\u201C",
+	"ldquor":              "\u201E",
+	"ldrdhar":             "\u2967",
+	"ldrushar":            "\u294B",
+	"ldsh":                "\u21B2",
+	"le":                  "\u2264",
+	"leftarrow":           "\u2190",
+	"leftarrowtail":       "\u21A2",
+	"leftharpoondown":     "\u21BD",
+	"leftharpoonup":       "\u21BC",
+	"leftleftarrows":      "\u21C7",
+	"leftrightarrow":      "\u2194",
+	"leftrightarrows":     "\u21C6",
+	"leftrightharpoons":   "\u21CB",
+	"leftrightsquigarrow": "\u21AD",
+	"leftthreetimes":      "\u22CB",
+	"leg":                 "\u22DA",
+	"leq":                 "\u2264",
+	"leqq":                "\u2266",
+	"leqslant":            "\u2A7D",
+	"les":                 "\u2A7D",
+	"lescc":               "\u2AA8",
+	"lesdot":              "\u2A7F",
+	"lesdoto":             "\u2A81",
+	"lesdotor":            "\u2A83",
+	"lesg":                "\u22DA\uFE00",
+	"lesges":              "\u2A93",
+	"lessapprox":          "\u2A85",
+	"lessdot":             "\u22D6",
+	"lesseqgtr":           "\u22DA",
+	"lesseqqgtr":          "\u2A8B",
+	"lessgtr":             "\u2276",
+	"lesssim":             "\u2272",
+	"lfisht":              "\u297C",
+	"lfloor":              "\u230A",
+	"lfr":                 "\U0001D529",
+	"lg":                  "\u2276",
+	"lgE":                 "\u2A91",
+	"lhard":               "\u21BD",
+	"lharu":               "\u21BC",
+	"lharul":              "\u296A",
+	"lhblk":               "\u2584",
+	"ljcy":                "\u0459",
+	"ll":                  "\u226A",
+	"llarr":               "\u21C7",
+	"llcorner":            "\u231E",
+	"llhard":              "\u296B",
+	"lltri":               "\u25FA",
+	"lmidot":              "\u0140",
+	"lmoust":              "\u23B0",
+	"lmoustache":          "\u23B0",
+	"lnE":                 "\u2268",
+	"lnap":                "\u2A89",
+	"lnapprox":            "\u2A89",
+	"lne":                 "\u2A87",
+	"lneq":                "\u2A87",
+	"lneqq":               "\u2268",
+	"lnsim":               "\u22E6",
+	"loang":               "\u27EC",
+	"loarr":               "\u21FD",
+	"lobrk":               "\u27E6",
+	"longleftarrow":       "\u27F5",
+	"longleftrightarrow":  "\u27F7",
+	"longmapsto":          "\u27FC",
+	"longrightarrow":      "\u27F6",
+	"looparrowleft":       "\u21AB",
+	"looparrowright":      "\u21AC",
+	"lopar":               "\u2985",
+	"lopf":                "\U0001D55D",
+	"loplus":              "\u2A2D",
+	"lotimes":             "\u2A34",
+	"lowast":              "\u2217",
+	"lowbar":              "\u005F",
+	"loz":                 "\u25CA",
+	"lozenge":             "\u25CA",
+	"lozf":                "\u29EB",
+	"lpar":                "\u0028",
+	"lparlt":              "\u2993",
+	"lrarr":               "\u21C6",
+	"lrcorner":            "\u231F",
+	"lrhar":               "\u21CB",
+	"lrhard":              "\u296D",
+	"lrm":                 "\u200E",
+	"lrtri":               "\u22BF",
+	"lsaquo":              "\u2039",
+	"lscr":                "\U0001D4C1",
+	"lsh":                 "\u21B0",
+	"lsim":                "\u2272",
+	"lsime":               "\u2A8D",
+	"lsimg":               "\u2A8F",
+	"lsqb":                "\u005B",
+	"lsquo":               "\u2018",
+	"lsquor":              "\u201A",
+	"lstrok":              "\u0142",
+	"lt":                  "\u003C",
+	"ltcc":                "\u2AA6",
+	"ltcir":               "\u2A79",
+	"ltdot":               "\u22D6",
+	"lthree":              "\u22CB",
+	"ltimes":              "\u22C9",
+	"ltlarr":              "\u2976",
+	"ltquest":             "\u2A7B",
+	"ltrPar":              "\u2996",
+	"ltri":                "\u25C3",
+	"ltrie":               "\u22B4",
+	"ltrif":               "\u25C2",
+	"lurdshar":            "\u294A",
+	"luruhar":             "\u2966",
+	"lvertneqq":           "\u2268\uFE00",
+	"lvnE":                "\u2268\uFE00",
+	"mDDot":               "\u223A",
+	"macr":                "\u00AF",
+	"male":                "\u2642",
+	"malt":                "\u2720",
+	"maltese":             "\u2720",
+	"map":                 "\u21A6",
+	"mapsto":              "\u21A6",
+	"mapstodown":          "\u21A7",
+	"mapstoleft":          "\u21A4",
+	"mapstoup":            "\u21A5",
+	"marker":              "\u25AE",
+	"mcomma":              "\u2A29",
+	"mcy":                 "\u043C",
+	"mdash":               "\u2014",
+	"measuredangle":       "\u2221",
+	"mfr":                 "\U0001D52A",
+	"mho":                 "\u2127",
+	"micro":               "\u00B5",
+	"mid":                 "\u2223",
+	"midast":              "\u002A",
+	"midcir":              "\u2AF0",
+	"middot":              "\u00B7",
+	"minus":               "\u2212",
+	"minusb":              "\u229F",
+	"minusd":              "\u2238",
+	"minusdu":             "\u2A2A",
+	"mlcp":                "\u2ADB",
+	"mldr":                "\u2026",
+	"mnplus":              "\u2213",
+	"models":              "\u22A7",
+	"mopf":                "\U0001D55E",
+	"mp":                  "\u2213",
+	"mscr":                "\U0001D4C2",
+	"mstpos":              "\u223E",
+	"mu":                  "\u03BC",
+	"multimap":            "\u22B8",
+	"mumap":               "\u22B8",
+	"nGg":                 "\u22D9\u0338",
+	"nGt":                 "\u226B\u20D2",
+	"nGtv":                "\u226B\u0338",
+	"nLeftarrow":          "\u21CD",
+	"nLeftrightarrow":     "\u21CE",
+	"nLl":                 "\u22D8\u0338",
+	"nLt":                 "\u226A\u20D2",
+	"nLtv":                "\u226A\u0338",
+	"nRightarrow":         "\u21CF",
+	"nVDash":              "\u22AF",
+	"nVdash":              "\u22AE",
+	"nabla":               "\u2207",
+	"nacute":              "\u0144",
+	"nang":                "\u2220\u20D2",
+	"nap":                 "\u2249",
+	"napE":                "\u2A70\u0338",
+	"napid":               "\u224B\u0338",
+	"napos":               "\u0149",
+	"napprox":             "\u2249",
+	"natur":               "\u266E",
+	"natural":             "\u266E",
+	"naturals":            "\u2115",
+	"nbsp":                "\u00A0",
+	"nbump":               "\u224E\u0338",
+	"nbumpe":              "\u224F\u0338",
+	"ncap":                "\u2A43",
+	"ncaron":              "\u0148",
+	"ncedil":              "\u0146",
+	"ncong":               "\u2247",
+	"ncongdot":            "\u2A6D\u0338",
+	"ncup":                "\u2A42",
+	"ncy":                 "\u043D",
+	"ndash":               "\u2013",
+	"ne":                  "\u2260",
+	"neArr":               "\u21D7",
+	"nearhk":              "\u2924",
+	"nearr":               "\u2197",
+	"nearrow":             "\u2197",
+	"nedot":               "\u2250\u0338",
+	"nequiv":              "\u2262",
+	"nesear":              "\u2928",
+	"nesim":               "\u2242\u0338",
+	"nexist":              "\u2204",
+	"nexists":             "\u2204",
+	"nfr":                 "\U0001D52B",
+	"ngE":                 "\u2267\u0338",
+	"nge":                 "\u2271",
+	"ngeq":                "\u2271",
+	"ngeqq":               "\u2267\u0338",
+	"ngeqslant":           "\u2A7E\u0338",
+	"nges":                "\u2A7E\u0338",
+	"ngsim":               "\u2275",
+	"ngt":                 "\u226F",
+	"ngtr":                "\u226F",
+	"nhArr":               "\u21CE",
+	"nharr":               "\u21AE",
+	"nhpar":               "\u2AF2",
+	"ni":                  "\u220B",
+	"nis":                 "\u22FC",
+	"nisd":                "\u22FA",
+	"niv":                 "\u220B",
+	"njcy":                "\u045A",
+	"nlArr":               "\u21CD",
+	"nlE":                 "\u2266\u0338",
+	"nlarr":               "\u219A",
+	"nldr":                "\u2025",
+	"nle":                 "\u2270",
+	"nleftarrow":          "\u219A",
+	"nleftrightarrow":     "\u21AE",
+	"nleq":                "\u2270",
+	"nleqq":               "\u2266\u0338",
+	"nleqslant":           "\u2A7D\u0338",
+	"nles":                "\u2A7D\u0338",
+	"nless":               "\u226E",
+	"nlsim":               "\u2274",
+	"nlt":                 "\u226E",
+	"nltri":               "\u22EA",
+	"nltrie":              "\u22EC",
+	"nmid":                "\u2224",
+	"nopf":                "\U0001D55F",
+	"not":                 "\u00AC",
+	"notin":               "\u2209",
+	"notinE":              "\u22F9\u0338",
+	"notindot":            "\u22F5\u0338",
+	"notinva":             "\u2209",
+	"notinvb":             "\u22F7",
+	"notinvc":             "\u22F6",
+	"notni":               "\u220C",
+	"notniva":             "\u220C",
+	"notnivb":             "\u22FE",
+	"notnivc":             "\u22FD",
+	"npar":                "\u2226",
+	"nparallel":           "\u2226",
+	"nparsl":              "\u2AFD\u20E5",
+	"npart":               "\u2202\u0338",
+	"npolint":             "\u2A14",
+	"npr":                 "\u2280",
+	"nprcue":              "\u22E0",
+	"npre":                "\u2AAF\u0338",
+	"nprec":               "\u2280",
+	"npreceq":             "\u2AAF\u0338",
+	"nrArr":               "\u21CF",
+	"nrarr":               "\u219B",
+	"nrarrc":              "\u2933\u0338",
+	"nrarrw":              "\u219D\u0338",
+	"nrightarrow":         "\u219B",
+	"nrtri":               "\u22EB",
+	"nrtrie":              "\u22ED",
+	"nsc":                 "\u2281",
+	"nsccue":              "\u22E1",
+	"nsce":                "\u2AB0\u0338",
+	"nscr":                "\U0001D4C3",
+	"nshortmid":           "\u2224",
+	"nshortparallel":      "\u2226",
+	"nsim":                "\u2241",
+	"nsime":               "\u2244",
+	"nsimeq":              "\u2244",
+	"nsmid":               "\u2224",
+	"nspar":               "\u2226",
+	"nsqsube":             "\u22E2",
+	"nsqsupe":             "\u22E3",
+	"nsub":                "\u2284",
+	"nsubE":               "\u2AC5\u0338",
+	"nsube":               "\u2288",
+	"nsubset":             "\u2282\u20D2",
+	"nsubseteq":           "\u2288",
+	"nsubseteqq":          "\u2AC5\u0338",
+	"nsucc":               "\u2281",
+	"nsucceq":             "\u2AB0\u0338",
+	"nsup":                "\u2285",
+	"nsupE":               "\u2AC6\u0338",
+	"nsupe":               "\u2289",
+	"nsupset":             "\u2283\u20D2",
+	"nsupseteq":           "\u2289",
+	"nsupseteqq":          "\u2AC6\u0338",
+	"ntgl":                "\u2279",
+	"ntilde":              "\u00F1",
+	"ntlg":                "\u2278",
+	"ntriangleleft":       "\u22EA",
+	"ntrianglelefteq":     "\u22EC",
+	"ntriangleright":      "\u22EB",
+	"ntrianglerighteq":    "\u22ED",
+	"nu":                  "\u03BD",
+	"num":                 "\u0023",
+	"numero":              "\u2116",
+	"numsp":               "\u2007",
+	"nvDash":              "\u22AD",
+	"nvHarr":              "\u2904",
+	"nvap":                "\u224D\u20D2",
+	"nvdash":              "\u22AC",
+	"nvge":                "\u2265\u20D2",
+	"nvgt":                "\u003E\u20D2",
+	"nvinfin":             "\u29DE",
+	"nvlArr":              "\u2902",
+	"nvle":                "\u2264\u20D2",
+	"nvlt":                "\u003C\u20D2",
+	"nvltrie":             "\u22B4\u20D2",
+	"nvrArr":              "\u2903",
+	"nvrtrie":             "\u22B5\u20D2",
+	"nvsim":               "\u223C\u20D2",
+	"nwArr":               "\u21D6",
+	"nwarhk":              "\u2923",
+	"nwarr":               "\u2196",
+	"nwarrow":             "\u2196",
+	"nwnear":              "\u2927",
+	"oS":                  "\u24C8",
+	"oacute":              "\u00F3",
+	"oast":                "\u229B",
+	"ocir":                "\u229A",
+	"ocirc":               "\u00F4",
+	"ocy":                 "\u043E",
+	"odash":               "\u229D",
+	"odblac":              "\u0151",
+	"odiv":                "\u2A38",
+	"odot":                "\u2299",
+	"odsold":              "\u29BC",
+	"oelig":               "\u0153",
+	"ofcir":               "\u29BF",
+	"ofr":                 "\U0001D52C",
+	"ogon":                "\u02DB",
+	"ograve":              "\u00F2",
+	"ogt":                 "\u29C1",
+	"ohbar":               "\u29B5",
+	"ohm":                 "\u03A9",
+	"oint":                "\u222E",
+	"olarr":               "\u21BA",
+	"olcir":               "\u29BE",
+	"olcross":             "\u29BB",
+	"oline":               "\u203E",
+	"olt":                 "\u29C0",
+	"omacr":               "\u014D",
+	"omega":               "\u03C9",
+	"omicron":             "\u03BF",
+	"omid":                "\u29B6",
+	"ominus":              "\u2296",
+	"oopf":                "\U0001D560",
+	"opar":                "\u29B7",
+	"operp":               "\u29B9",
+	"oplus":               "\u2295",
+	"or":                  "\u2228",
+	"orarr":               "\u21BB",
+	"ord":                 "\u2A5D",
+	"order":               "\u2134",
+	"orderof":             "\u2134",
+	"ordf":                "\u00AA",
+	"ordm":                "\u00BA",
+	"origof":              "\u22B6",
+	"oror":                "\u2A56",
+	"orslope":             "\u2A57",
+	"orv":                 "\u2A5B",
+	"oscr":                "\u2134",
+	"oslash":              "\u00F8",
+	"osol":                "\u2298",
+	"otilde":              "\u00F5",
+	"otimes":              "\u2297",
+	"otimesas":            "\u2A36",
+	"ouml":                "\u00F6",
+	"ovbar":               "\u233D",
+	"par":                 "\u2225",
+	"para":                "\u00B6",
+	"parallel":            "\u2225",
+	"parsim":              "\u2AF3",
+	"parsl":               "\u2AFD",
+	"part":                "\u2202",
+	"pcy":                 "\u043F",
+	"percnt":              "\u0025",
+	"period":              "\u002E",
+	"permil":              "\u2030",
+	"perp":                "\u22A5",
+	"pertenk":             "\u2031",
+	"pfr":                 "\U0001D52D",
+	"phi":                 "\u03C6",
+	"phiv":                "\u03D5",
+	"phmmat":              "\u2133",
+	"phone":               "\u260E",
+	"pi":                  "\u03C0",
+	"pitchfork":           "\u22D4",
+	"piv":                 "\u03D6",
+	"planck":              "\u210F",
+	"planckh":             "\u210E",
+	"plankv":              "\u210F",
+	"plus":                "\u002B",
+	"plusacir":            "\u2A23",
+	"plusb":               "\u229E",
+	"pluscir":             "\u2A22",
+	"plusdo":              "\u2214",
+	"plusdu":              "\u2A25",
+	"pluse":               "\u2A72",
+	"plusmn":              "\u00B1",
+	"plussim":             "\u2A26",
+	"plustwo":             "\u2A27",
+	"pm":                  "\u00B1",
+	"pointint":            "\u2A15",
+	"popf":                "\U0001D561",
+	"pound":               "\u00A3",
+	"pr":                  "\u227A",
+	"prE":                 "\u2AB3",
+	"prap":                "\u2AB7",
+	"prcue":               "\u227C",
+	"pre":                 "\u2AAF",
+	"prec":                "\u227A",
+	"precapprox":          "\u2AB7",
+	"preccurlyeq":         "\u227C",
+	"preceq":              "\u2AAF",
+	"precnapprox":         "\u2AB9",
+	"precneqq":            "\u2AB5",
+	"precnsim":            "\u22E8",
+	"precsim":             "\u227E",
+	"prime":               "\u2032",
+	"primes":              "\u2119",
+	"prnE":                "\u2AB5",
+	"prnap":               "\u2AB9",
+	"prnsim":              "\u22E8",
+	"prod":                "\u220F",
+	"profalar":            "\u232E",
+	"profline":            "\u2312",
+	"profsurf":            "\u2313",
+	"prop":                "\u221D",
+	"propto":              "\u221D",
+	"prsim":               "\u227E",
+	"prurel":              "\u22B0",
+	"pscr":                "\U0001D4C5",
+	"psi":                 "\u03C8",
+	"puncsp":              "\u2008",
+	"qfr":                 "\U0001D52E",
+	"qint":                "\u2A0C",
+	"qopf":                "\U0001D562",
+	"qprime":              "\u2057",
+	"qscr":                "\U0001D4C6",
+	"quaternions":         "\u210D",
+	"quatint":             "\u2A16",
+	"quest":               "\u003F",
+	"questeq":             "\u225F",
+	"quot":                "\u0022",
+	"rAarr":               "\u21DB",
+	"rArr":                "\u21D2",
+	"rAtail":              "\u291C",
+	"rBarr":               "\u290F",
+	"rHar":                "\u2964",
+	"race":                "\u223D\u0331",
+	"racute":              "\u0155",
+	"radic":               "\u221A",
+	"raemptyv":            "\u29B3",
+	"rang":                "\u27E9",
+	"rangd":               "\u2992",
+	"range":               "\u29A5",
+	"rangle":              "\u27E9",
+	"raquo":               "\u00BB",
+	"rarr":                "\u2192",
+	"rarrap":              "\u2975",
+	"rarrb":               "\u21E5",
+	"rarrbfs":             "\u2920",
+	"rarrc":               "\u2933",
+	"rarrfs":              "\u291E",
+	"rarrhk":              "\u21AA",
+	"rarrlp":              "\u21AC",
+	"rarrpl":              "\u2945",
+	"rarrsim":             "\u2974",
+	"rarrtl":              "\u21A3",
+	"rarrw":               "\u219D",
+	"ratail":              "\u291A",
+	"ratio":               "\u2236",
+	"rationals":           "\u211A",
+	"rbarr":               "\u290D",
+	"rbbrk":               "\u2773",
+	"rbrace":              "\u007D",
+	"rbrack":              "\u005D",
+	"rbrke":               "\u298C",
+	"rbrksld":             "\u298E",
+	"rbrkslu":             "\u2990",
+	"rcaron":              "\u0159",
+	"rcedil":              "\u0157",
+	"rceil":               "\u2309",
+	"rcub":                "\u007D",
+	"rcy":                 "\u0440",
+	"rdca":                "\u2937",
+	"rdldhar":             "\u2969",
+	"rdquo":               "\u201D",
+	"rdquor":              "\u201D",
+	"rdsh":                "\u21B3",
+	"real":                "\u211C",
+	"realine":             "\u211B",
+	"realpart":            "\u211C",
+	"reals":               "\u211D",
+	"rect":                "\u25AD",
+	"reg":                 "\u00AE",
+	"rfisht":              "\u297D",
+	"rfloor":              "\u230B",
+	"rfr":                 "\U0001D52F",
+	"rhard":               "\u21C1",
+	"rharu":               "\u21C0",
+	"rharul":              "\u296C",
+	"rho":                 "\u03C1",
+	"rhov":                "\u03F1",
+	"rightarrow":          "\u2192",
+	"rightarrowtail":      "\u21A3",
+	"rightharpoondown":    "\u21C1",
+	"rightharpoonup":      "\u21C0",
+	"rightleftarrows":     "\u21C4",
+	"rightleftharpoons":   "\u21CC",
+	"rightrightarrows":    "\u21C9",
+	"rightsquigarrow":     "\u219D",
+	"rightthreetimes":     "\u22CC",
+	"ring":                "\u02DA",
+	"risingdotseq":        "\u2253",
+	"rlarr":               "\u21C4",
+	"rlhar":               "\u21CC",
+	"rlm":                 "\u200F",
+	"rmoust":              "\u23B1",
+	"rmoustache":          "\u23B1",
+	"rnmid":               "\u2AEE",
+	"roang":               "\u27ED",
+	"roarr":               "\u21FE",
+	"robrk":               "\u27E7",
+	"ropar":               "\u2986",
+	"ropf":                "\U0001D563",
+	"roplus":              "\u2A2E",
+	"rotimes":             "\u2A35",
+	"rpar":                "\u0029",
+	"rpargt":              "\u2994",
+	"rppolint":            "\u2A12",
+	"rrarr":               "\u21C9",
+	"rsaquo":              "\u203A",
+	"rscr":                "\U0001D4C7",
+	"rsh":                 "\u21B1",
+	"rsqb":                "\u005D",
+	"rsquo":               "\u2019",
+	"rsquor":              "\u2019",
+	"rthree":              "\u22CC",
+	"rtimes":              "\u22CA",
+	"rtri":                "\u25B9",
+	"rtrie":               "\u22B5",
+	"rtrif":               "\u25B8",
+	"rtriltri":            "\u29CE",
+	"ruluhar":             "\u2968",
+	"rx":                  "\u211E",
+	"sacute":              "\u015B",
+	"sbquo":               "\u201A",
+	"sc":                  "\u227B",
+	"scE":                 "\u2AB4",
+	"scap":                "\u2AB8",
+	"scaron":              "\u0161",
+	"sccue":               "\u227D",
+	"sce":                 "\u2AB0",
+	"scedil":              "\u015F",
+	"scirc":               "\u015D",
+	"scnE":                "\u2AB6",
+	"scnap":               "\u2ABA",
+	"scnsim":              "\u22E9",
+	"scpolint":            "\u2A13",
+	"scsim":               "\u227F",
+	"scy":                 "\u0441",
+	"sdot":                "\u22C5",
+	"sdotb":               "\u22A1",
+	"sdote":               "\u2A66",
+	"seArr":               "\u21D8",
+	"searhk":              "\u2925",
+	"searr":               "\u2198",
+	"searrow":             "\u2198",
+	"sect":                "\u00A7",
+	"semi":                "\u003B",
+	"seswar":              "\u2929",
+	"setminus":            "\u2216",
+	"setmn":               "\u2216",
+	"sext":                "\u2736",
+	"sfr":                 "\U0001D530",
+	"sfrown":              "\u2322",
+	"sharp":               "\u266F",
+	"shchcy":              "\u0449",
+	"shcy":                "\u0448",
+	"shortmid":            "\u2223",
+	"shortparallel":       "\u2225",
+	"shy":                 "\u00AD",
+	"sigma":               "\u03C3",
+	"sigmaf":              "\u03C2",
+	"sigmav":              "\u03C2",
+	"sim":                 "\u223C",
+	"simdot":              "\u2A6A",
+	"sime":                "\u2243",
+	"simeq":               "\u2243",
+	"simg":                "\u2A9E",
+	"simgE":               "\u2AA0",
+	"siml":                "\u2A9D",
+	"simlE":               "\u2A9F",
+	"simne":               "\u2246",
+	"simplus":             "\u2A24",
+	"simrarr":             "\u2972",
+	"slarr":               "\u2190",
+	"smallsetminus":       "\u2216",
+	"smashp":              "\u2A33",
+	"smeparsl":            "\u29E4",
+	"smid":                "\u2223",
+	"smile":               "\u2323",
+	"smt":                 "\u2AAA",
+	"smte":                "\u2AAC",
+	"smtes":               "\u2AAC\uFE00",
+	"softcy":              "\u044C",
+	"sol":                 "\u002F",
+	"solb":                "\u29C4",
+	"solbar":              "\u233F",
+	"sopf":                "\U0001D564",
+	"spades":              "\u2660",
+	"spadesuit":           "\u2660",
+	"spar":                "\u2225",
+	"sqcap":               "\u2293",
+	"sqcaps":              "\u2293\uFE00",
+	"sqcup":               "\u2294",
+	"sqcups":              "\u2294\uFE00",
+	"sqsub":               "\u228F",
+	"sqsube":              "\u2291",
+	"sqsubset":            "\u228F",
+	"sqsubseteq":          "\u2291",
+	"sqsup":               "\u2290",
+	"sqsupe":              "\u2292",
+	"sqsupset":            "\u2290",
+	"sqsupseteq":          "\u2292",
+	"squ":                 "\u25A1",
+	"square":              "\u25A1",
+	"squarf":              "\u25AA",
+	"squf":                "\u25AA",
+	"srarr":               "\u2192",
+	"sscr":                "\U0001D4C8",
+	"ssetmn":              "\u2216",
+	"ssmile":              "\u2323",
+	"sstarf":              "\u22C6",
+	"star":                "\u2606",
+	"starf":               "\u2605",
+	"straightepsilon":     "\u03F5",
+	"straightphi":         "\u03D5",
+	"strns":               "\u00AF",
+	"sub":                 "\u2282",
+	"subE":                "\u2AC5",
+	"subdot":              "\u2ABD",
+	"sube":                "\u2286",
+	"subedot":             "\u2AC3",
+	"submult":             "\u2AC1",
+	"subnE":               "\u2ACB",
+	"subne":               "\u228A",
+	"subplus":             "\u2ABF",
+	"subrarr":             "\u2979",
+	"subset":              "\u2282",
+	"subseteq":            "\u2286",
+	"subseteqq":           "\u2AC5",
+	"subsetneq":           "\u228A",
+	"subsetneqq":          "\u2ACB",
+	"subsim":              "\u2AC7",
+	"subsub":              "\u2AD5",
+	"subsup":              "\u2AD3",
+	"succ":                "\u227B",
+	"succapprox":          "\u2AB8",
+	"succcurlyeq":         "\u227D",
+	"succeq":              "\u2AB0",
+	"succnapprox":         "\u2ABA",
+	"succneqq":            "\u2AB6",
+	"succnsim":            "\u22E9",
+	"succsim":             "\u227F",
+	"sum":                 "\u2211",
+	"sung":                "\u266A",
+	"sup":                 "\u2283",
+	"sup1":                "\u00B9",
+	"sup2":                "\u00B2",
+	"sup3":                "\u00B3",
+	"supE":                "\u2AC6",
+	"supdot":              "\u2ABE",
+	"supdsub":             "\u2AD8",
+	"supe":                "\u2287",
+	"supedot":             "\u2AC4",
+	"suphsol":             "\u27C9",
+	"suphsub":             "\u2AD7",
+	"suplarr":             "\u297B",
+	"supmult":             "\u2AC2",
+	"supnE":               "\u2ACC",
+	"supne":               "\u228B",
+	"supplus":             "\u2AC0",
+	"supset":              "\u2283",
+	"supseteq":            "\u2287",
+	"supseteqq":           "\u2AC6",
+	"supsetneq":           "\u228B",
+	"supsetneqq":          "\u2ACC",
+	"supsim":              "\u2AC8",
+	"supsub":              "\u2AD4",
+	"supsup":              "\u2AD6",
+	"swArr":               "\u21D9",
+	"swarhk":              "\u2926",
+	"swarr":               "\u2199",
+	"swarrow":             "\u2199",
+	"swnwar":              "\u292A",
+	"szlig":               "\u00DF",
+	"target":              "\u2316",
+	"tau":                 "\u03C4",
+	"tbrk":                "\u23B4",
+	"tcaron":              "\u0165",
+	"tcedil":              "\u0163",
+	"tcy":                 "\u0442",
+	"tdot":                "\u20DB",
+	"telrec":              "\u2315",
+	"tfr":                 "\U0001D531",
+	"there4":              "\u2234",
+	"therefore":           "\u2234",
+	"theta":               "\u03B8",
+	"thetasym":            "\u03D1",
+	"thetav":              "\u03D1",
+	"thickapprox":         "\u2248",
+	"thicksim":            "\u223C",
+	"thinsp":              "\u2009",
+	"thkap":               "\u2248",
+	"thksim":              "\u223C",
+	"thorn":               "\u00FE",
+	"tilde":               "\u02DC",
+	"times":               "\u00D7",
+	"timesb":              "\u22A0",
+	"timesbar":            "\u2A31",
+	"timesd":              "\u2A30",
+	"tint":                "\u222D",
+	"toea":                "\u2928",
+	"top":                 "\u22A4",
+	"topbot":              "\u2336",
+	"topcir":              "\u2AF1",
+	"topf":                "\U0001D565",
+	"topfork":             "\u2ADA",
+	"tosa":                "\u2929",
+	"tprime":              "\u2034",
+	"trade":               "\u2122",
+	"triangle":            "\u25B5",
+	"triangledown":        "\u25BF",
+	"triangleleft":        "\u25C3",
+	"trianglelefteq":      "\u22B4",
+	"triangleq":           "\u225C",
+	"triangleright":       "\u25B9",
+	"trianglerighteq":     "\u22B5",
+	"tridot":              "\u25EC",
+	"trie":                "\u225C",
+	"triminus":            "\u2A3A",
+	"triplus":             "\u2A39",
+	"trisb":               "\u29CD",
+	"tritime":             "\u2A3B",
+	"trpezium":            "\u23E2",
+	"tscr":                "\U0001D4C9",
+	"tscy":                "\u0446",
+	"tshcy":               "\u045B",
+	"tstrok":              "\u0167",
+	"twixt":               "\u226C",
+	"twoheadleftarrow":    "\u219E",
+	"twoheadrightarrow":   "\u21A0",
+	"uArr":                "\u21D1",
+	"uHar":                "\u2963",
+	"uacute":              "\u00FA",
+	"uarr":                "\u2191",
+	"ubrcy":               "\u045E",
+	"ubreve":              "\u016D",
+	"ucirc":               "\u00FB",
+	"ucy":                 "\u0443",
+	"udarr":               "\u21C5",
+	"udblac":              "\u0171",
+	"udhar":               "\u296E",
+	"ufisht":              "\u297E",
+	"ufr":                 "\U0001D532",
+	"ugrave":              "\u00F9",
+	"uharl":               "\u21BF",
+	"uharr":               "\u21BE",
+	"uhblk":               "\u2580",
+	"ulcorn":              "\u231C",
+	"ulcorner":            "\u231C",
+	"ulcrop":              "\u230F",
+	"ultri":               "\u25F8",
+	"umacr":               "\u016B",
+	"uml":                 "\u00A8",
+	"uogon":               "\u0173",
+	"uopf":                "\U0001D566",
+	"uparrow":             "\u2191",
+	"updownarrow":         "\u2195",
+	"upharpoonleft":       "\u21BF",
+	"upharpoonright":      "\u21BE",
+	"uplus":               "\u228E",
+	"upsi":                "\u03C5",
+	"upsih":               "\u03D2",
+	"upsilon":             "\u03C5",
+	"upuparrows":          "\u21C8",
+	"urcorn":              "\u231D",
+	"urcorner":            "\u231D",
+	"urcrop":              "\u230E",
+	"uring":               "\u016F",
+	"urtri":               "\u25F9",
+	"uscr":                "\U0001D4CA",
+	"utdot":               "\u22F0",
+	"utilde":              "\u0169",
+	"utri":                "\u25B5",
+	"utrif":               "\u25B4",
+	"uuarr":               "\u21C8",
+	"uuml":                "\u00FC",
+	"uwangle":             "\u29A7",
+	"vArr":                "\u21D5",
+	"vBar":                "\u2AE8",
+	"vBarv":               "\u2AE9",
+	"vDash":               "\u22A8",
+	"vangrt":              "\u299C",
+	"varepsilon":          "\u03F5",
+	"varkappa":            "\u03F0",
+	"varnothing":          "\u2205",
+	"varphi":              "\u03D5",
+	"varpi":               "\u03D6",
+	"varpropto":           "\u221D",
+	"varr":                "\u2195",
+	"varrho":              "\u03F1",
+	"varsigma":            "\u03C2",
+	"varsubsetneq":        "\u228A\uFE00",
+	"varsubsetneqq":       "\u2ACB\uFE00",
+	"varsupsetneq":        "\u228B\uFE00",
+	"varsupsetneqq":       "\u2ACC\uFE00",
+	"vartheta":            "\u03D1",
+	"vartriangleleft":     "\u22B2",
+	"vartriangleright":    "\u22B3",
+	"vcy":                 "\u0432",
+	"vdash":               "\u22A2",
+	"vee":                 "\u2228",
+	"veebar":              "\u22BB",
+	"veeeq":               "\u225A",
+	"vellip":              "\u22EE",
+	"verbar":              "\u007C",
+	"vert":                "\u007C",
+	"vfr":                 "\U0001D533",
+	"vltri":               "\u22B2",
+	"vnsub":               "\u2282\u20D2",
+	"vnsup":               "\u2283\u20D2",
+	"vopf":                "\U0001D567",
+	"vprop":               "\u221D",
+	"vrtri":               "\u22B3",
+	"vscr":                "\U0001D4CB",
+	"vsubnE":              "\u2ACB\uFE00",
+	"vsubne":              "\u228A\uFE00",
+	"vsupnE":              "\u2ACC\uFE00",
+	"vsupne":              "\u228B\uFE00",
+	"vzigzag":             "\u299A",
+	"wcirc":               "\u0175",
+	"wedbar":              "\u2A5F",
+	"wedge":               "\u2227",
+	"wedgeq":              "\u2259",
+	"weierp":              "\u2118",
+	"wfr":                 "\U0001D534",
+	"wopf":                "\U0001D568",
+	"wp":                  "\u2118",
+	"wr":                  "\u2240",
+	"wreath":              "\u2240",
+	"wscr":                "\U0001D4CC",
+	"xcap":                "\u22C2",
+	"xcirc":               "\u25EF",
+	"xcup":                "\u22C3",
+	"xdtri":               "\u25BD",
+	"xfr":                 "\U0001D535",
+	"xhArr":               "\u27FA",
+	"xharr":               "\u27F7",
+	"xi":                  "\u03BE",
+	"xlArr":               "\u27F8",
+	"xlarr":               "\u27F5",
+	"xmap":                "\u27FC",
+	"xnis":                "\u22FB",
+	"xodot":               "\u2A00",
+	"xopf":                "\U0001D569",
+	"xoplus":              "\u2A01",
+	"xotime":              "\u2A02",
+	"xrArr":               "\u27F9",
+	"xrarr":               "\u27F6",
+	"xscr":                "\U0001D4CD",
+	"xsqcup":              "\u2A06",
+	"xuplus":              "\u2A04",
+	"xutri":               "\u25B3",
+	"xvee":                "\u22C1",
+	"xwedge":              "\u22C0",
+	"yacute":              "\u00FD",
+	"yacy":                "\u044F",
+	"ycirc":               "\u0177",
+	"ycy":                 "\u044B",
+	"yen":                 "\u00A5",
+	"yfr":                 "\U0001D536",
+	"yicy":                "\u0457",
+	"yopf":                "\U0001D56A",
+	"yscr":                "\U0001D4CE",
+	"yucy":                "\u044E",
+	"yuml":                "\u00FF",
+	"zacute":              "\u017A",
+	"zcaron":              "\u017E",
+	"zcy":                 "\u0437",
+	"zdot":                "\u017C",
+	"zeetrf":              "\u2128",
+	"zeta":                "\u03B6",
+	"zfr":                 "\U0001D537",
+	"zhcy":                "\u0436",
+	"zigrarr":             "\u21DD",
+	"zopf":                "\U0001D56B",
+	"zscr":                "\U0001D4CF",
+	"zwj":                 "\u200D",
+	"zwnj":                "\u200C",
+}
diff --git a/utils/markdown/indented_code.go b/utils/markdown/indented_code.go
new file mode 100644
index 000000000..dc5dce1ac
--- /dev/null
+++ b/utils/markdown/indented_code.go
@@ -0,0 +1,98 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type IndentedCodeLine struct {
+	Indentation int
+	Range       Range
+}
+
+type IndentedCode struct {
+	blockBase
+	markdown string
+
+	RawCode []IndentedCodeLine
+}
+
+func (b *IndentedCode) Code() (result string) {
+	for _, code := range b.RawCode {
+		result += strings.Repeat(" ", code.Indentation) + b.markdown[code.Range.Position:code.Range.End]
+	}
+	return
+}
+
+func (b *IndentedCode) Continuation(indentation int, r Range) *continuation {
+	if indentation >= 4 {
+		return &continuation{
+			Indentation: indentation - 4,
+			Remaining:   r,
+		}
+	}
+	s := b.markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		return &continuation{
+			Remaining: r,
+		}
+	}
+	return nil
+}
+
+func (b *IndentedCode) AddLine(indentation int, r Range) bool {
+	b.RawCode = append(b.RawCode, IndentedCodeLine{
+		Indentation: indentation,
+		Range:       r,
+	})
+	return true
+}
+
+func (b *IndentedCode) Close() {
+	for {
+		last := b.RawCode[len(b.RawCode)-1]
+		s := b.markdown[last.Range.Position:last.Range.End]
+		if strings.TrimRight(s, "\r\n") == "" {
+			b.RawCode = b.RawCode[:len(b.RawCode)-1]
+		} else {
+			break
+		}
+	}
+}
+
+func (b *IndentedCode) AllowsBlockStarts() bool {
+	return false
+}
+
+func indentedCodeStart(markdown string, indentation int, r Range, matchedBlocks, unmatchedBlocks []Block) []Block {
+	if len(unmatchedBlocks) > 0 {
+		if _, ok := unmatchedBlocks[len(unmatchedBlocks)-1].(*Paragraph); ok {
+			return nil
+		}
+	} else if len(matchedBlocks) > 0 {
+		if _, ok := matchedBlocks[len(matchedBlocks)-1].(*Paragraph); ok {
+			return nil
+		}
+	}
+
+	if indentation < 4 {
+		return nil
+	}
+
+	s := markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		return nil
+	}
+
+	return []Block{
+		&IndentedCode{
+			markdown: markdown,
+			RawCode: []IndentedCodeLine{{
+				Indentation: indentation - 4,
+				Range:       r,
+			}},
+		},
+	}
+}
diff --git a/utils/markdown/inlines.go b/utils/markdown/inlines.go
new file mode 100644
index 000000000..03da2f15c
--- /dev/null
+++ b/utils/markdown/inlines.go
@@ -0,0 +1,489 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"container/list"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+type Inline interface {
+	IsInline() bool
+}
+
+type inlineBase struct{}
+
+func (inlineBase) IsInline() bool { return true }
+
+type Text struct {
+	inlineBase
+
+	Text string
+}
+
+type CodeSpan struct {
+	inlineBase
+
+	Code string
+}
+
+type HardLineBreak struct {
+	inlineBase
+}
+
+type SoftLineBreak struct {
+	inlineBase
+}
+
+type InlineLinkOrImage struct {
+	inlineBase
+
+	Children []Inline
+
+	RawDestination Range
+
+	markdown string
+	rawTitle string
+}
+
+func (i *InlineLinkOrImage) Destination() string {
+	return Unescape(i.markdown[i.RawDestination.Position:i.RawDestination.End])
+}
+
+func (i *InlineLinkOrImage) Title() string {
+	return Unescape(i.rawTitle)
+}
+
+type InlineLink struct {
+	InlineLinkOrImage
+}
+
+type InlineImage struct {
+	InlineLinkOrImage
+}
+
+type ReferenceLinkOrImage struct {
+	inlineBase
+	*ReferenceDefinition
+
+	Children []Inline
+}
+
+type ReferenceLink struct {
+	ReferenceLinkOrImage
+}
+
+type ReferenceImage struct {
+	ReferenceLinkOrImage
+}
+
+type delimiterType int
+
+const (
+	linkOpeningDelimiter delimiterType = iota
+	imageOpeningDelimiter
+)
+
+type delimiter struct {
+	Type       delimiterType
+	IsInactive bool
+	TextNode   int
+	Range      Range
+}
+
+type inlineParser struct {
+	markdown             string
+	ranges               []Range
+	referenceDefinitions []*ReferenceDefinition
+
+	raw            string
+	position       int
+	inlines        []Inline
+	delimiterStack *list.List
+}
+
+func newInlineParser(markdown string, ranges []Range, referenceDefinitions []*ReferenceDefinition) *inlineParser {
+	return &inlineParser{
+		markdown:             markdown,
+		ranges:               ranges,
+		referenceDefinitions: referenceDefinitions,
+		delimiterStack:       list.New(),
+	}
+}
+
+func (p *inlineParser) parseBackticks() {
+	count := 1
+	for i := p.position + 1; i < len(p.raw) && p.raw[i] == '`'; i++ {
+		count++
+	}
+	opening := p.raw[p.position : p.position+count]
+	search := p.position + count
+	for search < len(p.raw) {
+		end := strings.Index(p.raw[search:], opening)
+		if end == -1 {
+			break
+		}
+		if search+end+count < len(p.raw) && p.raw[search+end+count] == '`' {
+			search += end + count
+			for search < len(p.raw) && p.raw[search] == '`' {
+				search++
+			}
+			continue
+		}
+		code := strings.Join(strings.Fields(p.raw[p.position+count:search+end]), " ")
+		p.position = search + end + count
+		p.inlines = append(p.inlines, &CodeSpan{
+			Code: code,
+		})
+		return
+	}
+	p.position += len(opening)
+	p.inlines = append(p.inlines, &Text{
+		Text: opening,
+	})
+}
+
+func (p *inlineParser) parseLineEnding() {
+	if p.position >= 1 && p.raw[p.position-1] == '\t' {
+		p.inlines = append(p.inlines, &HardLineBreak{})
+	} else if p.position >= 2 && p.raw[p.position-1] == ' ' && (p.raw[p.position-2] == '\t' || p.raw[p.position-1] == ' ') {
+		p.inlines = append(p.inlines, &HardLineBreak{})
+	} else {
+		p.inlines = append(p.inlines, &SoftLineBreak{})
+	}
+	p.position++
+	if p.position < len(p.raw) && p.raw[p.position] == '\n' {
+		p.position++
+	}
+}
+
+func (p *inlineParser) parseEscapeCharacter() {
+	if p.position+1 < len(p.raw) && isEscapableByte(p.raw[p.position+1]) {
+		p.inlines = append(p.inlines, &Text{
+			Text: string(p.raw[p.position+1]),
+		})
+		p.position += 2
+	} else {
+		p.inlines = append(p.inlines, &Text{
+			Text: `\`,
+		})
+		p.position++
+	}
+}
+
+func (p *inlineParser) parseText() {
+	if next := strings.IndexAny(p.raw[p.position:], "\r\n\\`&![]"); next == -1 {
+		p.inlines = append(p.inlines, &Text{
+			Text: strings.TrimRightFunc(p.raw[p.position:], isWhitespace),
+		})
+		p.position = len(p.raw)
+	} else {
+		if p.raw[p.position+next] == '\r' || p.raw[p.position+next] == '\n' {
+			p.inlines = append(p.inlines, &Text{
+				Text: strings.TrimRightFunc(p.raw[p.position:p.position+next], isWhitespace),
+			})
+		} else {
+			p.inlines = append(p.inlines, &Text{
+				Text: p.raw[p.position : p.position+next],
+			})
+		}
+		p.position += next
+	}
+}
+
+func (p *inlineParser) parseLinkOrImageDelimiter() {
+	if p.raw[p.position] == '[' {
+		p.inlines = append(p.inlines, &Text{
+			Text: "[",
+		})
+		p.delimiterStack.PushBack(&delimiter{
+			Type:     linkOpeningDelimiter,
+			TextNode: len(p.inlines) - 1,
+			Range:    Range{p.position, p.position + 1},
+		})
+		p.position++
+	} else if p.raw[p.position] == '!' && p.position+1 < len(p.raw) && p.raw[p.position+1] == '[' {
+		p.inlines = append(p.inlines, &Text{
+			Text: "![",
+		})
+		p.delimiterStack.PushBack(&delimiter{
+			Type:     imageOpeningDelimiter,
+			TextNode: len(p.inlines) - 1,
+			Range:    Range{p.position, p.position + 2},
+		})
+		p.position += 2
+	} else {
+		p.inlines = append(p.inlines, &Text{
+			Text: "!",
+		})
+		p.position++
+	}
+}
+
+func (p *inlineParser) peekAtInlineLinkDestinationAndTitle(position int) (destination, title Range, end int, ok bool) {
+	if position >= len(p.raw) || p.raw[position] != '(' {
+		return
+	}
+	position++
+
+	destinationStart := nextNonWhitespace(p.raw, position)
+	if destinationStart >= len(p.raw) {
+		return
+	} else if p.raw[destinationStart] == ')' {
+		return Range{destinationStart, destinationStart}, Range{destinationStart, destinationStart}, destinationStart + 1, true
+	}
+
+	destination, end, ok = parseLinkDestination(p.raw, destinationStart)
+	if !ok {
+		return
+	}
+	position = end
+
+	if position < len(p.raw) && isWhitespaceByte(p.raw[position]) {
+		titleStart := nextNonWhitespace(p.raw, position)
+		if titleStart >= len(p.raw) {
+			return
+		} else if p.raw[titleStart] == ')' {
+			return destination, Range{titleStart, titleStart}, titleStart + 1, true
+		}
+
+		title, end, ok = parseLinkTitle(p.raw, titleStart)
+		if !ok {
+			return
+		}
+		position = end
+	}
+
+	closingPosition := nextNonWhitespace(p.raw, position)
+	if closingPosition >= len(p.raw) || p.raw[closingPosition] != ')' {
+		return Range{}, Range{}, 0, false
+	}
+
+	return destination, title, closingPosition + 1, true
+}
+
+func (p *inlineParser) referenceDefinition(label string) *ReferenceDefinition {
+	clean := strings.Join(strings.Fields(label), " ")
+	for _, d := range p.referenceDefinitions {
+		if strings.EqualFold(clean, strings.Join(strings.Fields(d.Label()), " ")) {
+			return d
+		}
+	}
+	return nil
+}
+
+func (p *inlineParser) lookForLinkOrImage() {
+	for element := p.delimiterStack.Back(); element != nil; element = element.Prev() {
+		d := element.Value.(*delimiter)
+		if d.Type != imageOpeningDelimiter && d.Type != linkOpeningDelimiter {
+			continue
+		}
+		if d.IsInactive {
+			p.delimiterStack.Remove(element)
+			break
+		}
+
+		var inline Inline
+
+		if destination, title, next, ok := p.peekAtInlineLinkDestinationAndTitle(p.position + 1); ok {
+			destinationMarkdownPosition := relativeToAbsolutePosition(p.ranges, destination.Position)
+			linkOrImage := InlineLinkOrImage{
+				Children:       append([]Inline(nil), p.inlines[d.TextNode+1:]...),
+				RawDestination: Range{destinationMarkdownPosition, destinationMarkdownPosition + destination.End - destination.Position},
+				markdown:       p.markdown,
+				rawTitle:       p.raw[title.Position:title.End],
+			}
+			if d.Type == imageOpeningDelimiter {
+				inline = &InlineImage{linkOrImage}
+			} else {
+				inline = &InlineLink{linkOrImage}
+			}
+			p.position = next
+		} else {
+			referenceLabel := ""
+			label, next, hasLinkLabel := parseLinkLabel(p.raw, p.position+1)
+			if hasLinkLabel && label.End > label.Position {
+				referenceLabel = p.raw[label.Position:label.End]
+			} else {
+				referenceLabel = p.raw[d.Range.End:p.position]
+				if !hasLinkLabel {
+					next = p.position + 1
+				}
+			}
+			if referenceLabel != "" {
+				if reference := p.referenceDefinition(referenceLabel); reference != nil {
+					linkOrImage := ReferenceLinkOrImage{
+						ReferenceDefinition: reference,
+						Children:            append([]Inline(nil), p.inlines[d.TextNode+1:]...),
+					}
+					if d.Type == imageOpeningDelimiter {
+						inline = &ReferenceImage{linkOrImage}
+					} else {
+						inline = &ReferenceLink{linkOrImage}
+					}
+					p.position = next
+				}
+			}
+		}
+
+		if inline != nil {
+			if d.Type == imageOpeningDelimiter {
+				p.inlines = append(p.inlines[:d.TextNode], inline)
+			} else {
+				p.inlines = append(p.inlines[:d.TextNode], inline)
+				for element := element.Prev(); element != nil; element = element.Prev() {
+					if d := element.Value.(*delimiter); d.Type == linkOpeningDelimiter {
+						d.IsInactive = true
+					}
+				}
+			}
+			p.delimiterStack.Remove(element)
+			return
+		} else {
+			p.delimiterStack.Remove(element)
+			break
+		}
+	}
+	p.inlines = append(p.inlines, &Text{
+		Text: "]",
+	})
+	p.position++
+}
+
+func CharacterReference(ref string) string {
+	if ref == "" {
+		return ""
+	}
+	if ref[0] == '#' {
+		if len(ref) < 2 {
+			return ""
+		}
+		n := 0
+		if ref[1] == 'X' || ref[1] == 'x' {
+			if len(ref) < 3 {
+				return ""
+			}
+			for i := 2; i < len(ref); i++ {
+				if i > 9 {
+					return ""
+				}
+				d := ref[i]
+				switch {
+				case d >= '0' && d <= '9':
+					n = n*16 + int(d-'0')
+				case d >= 'a' && d <= 'f':
+					n = n*16 + 10 + int(d-'a')
+				case d >= 'A' && d <= 'F':
+					n = n*16 + 10 + int(d-'A')
+				default:
+					return ""
+				}
+			}
+		} else {
+			for i := 1; i < len(ref); i++ {
+				if i > 8 || ref[i] < '0' || ref[i] > '9' {
+					return ""
+				}
+				n = n*10 + int(ref[i]-'0')
+			}
+		}
+		c := rune(n)
+		if c == '\u0000' || !utf8.ValidRune(c) {
+			return string(unicode.ReplacementChar)
+		}
+		return string(c)
+	}
+	if entity, ok := htmlEntities[ref]; ok {
+		return entity
+	}
+	return ""
+}
+
+func (p *inlineParser) parseCharacterReference() {
+	p.position++
+	if semicolon := strings.IndexByte(p.raw[p.position:], ';'); semicolon == -1 {
+		p.inlines = append(p.inlines, &Text{
+			Text: "&",
+		})
+	} else if s := CharacterReference(p.raw[p.position : p.position+semicolon]); s != "" {
+		p.position += semicolon + 1
+		p.inlines = append(p.inlines, &Text{
+			Text: s,
+		})
+	} else {
+		p.inlines = append(p.inlines, &Text{
+			Text: "&",
+		})
+	}
+}
+
+func (p *inlineParser) Parse() []Inline {
+	for _, r := range p.ranges {
+		p.raw += p.markdown[r.Position:r.End]
+	}
+
+	for p.position < len(p.raw) {
+		c, _ := utf8.DecodeRuneInString(p.raw[p.position:])
+
+		switch c {
+		case '\r', '\n':
+			p.parseLineEnding()
+		case '\\':
+			p.parseEscapeCharacter()
+		case '`':
+			p.parseBackticks()
+		case '&':
+			p.parseCharacterReference()
+		case '!', '[':
+			p.parseLinkOrImageDelimiter()
+		case ']':
+			p.lookForLinkOrImage()
+		default:
+			p.parseText()
+		}
+	}
+
+	return p.inlines
+}
+
+func ParseInlines(markdown string, ranges []Range, referenceDefinitions []*ReferenceDefinition) (inlines []Inline) {
+	return newInlineParser(markdown, ranges, referenceDefinitions).Parse()
+}
+
+func Unescape(markdown string) string {
+	ret := ""
+
+	position := 0
+	for position < len(markdown) {
+		c, cSize := utf8.DecodeRuneInString(markdown[position:])
+
+		switch c {
+		case '\\':
+			if position+1 < len(markdown) && isEscapableByte(markdown[position+1]) {
+				ret += string(markdown[position+1])
+				position += 2
+			} else {
+				ret += `\`
+				position++
+			}
+		case '&':
+			position++
+			if semicolon := strings.IndexByte(markdown[position:], ';'); semicolon == -1 {
+				ret += "&"
+			} else if s := CharacterReference(markdown[position : position+semicolon]); s != "" {
+				position += semicolon + 1
+				ret += s
+			} else {
+				ret += "&"
+			}
+		default:
+			ret += string(c)
+			position += cSize
+		}
+	}
+
+	return ret
+}
diff --git a/utils/markdown/inspect.go b/utils/markdown/inspect.go
new file mode 100644
index 000000000..c4e3bf1ac
--- /dev/null
+++ b/utils/markdown/inspect.go
@@ -0,0 +1,78 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+// Inspect traverses the markdown tree in depth-first order. If f returns true, Inspect invokes f
+// recursively for each child of the block or inline, followed by a call of f(nil).
+func Inspect(markdown string, f func(interface{}) bool) {
+	document, referenceDefinitions := Parse(markdown)
+	InspectBlock(document, func(block Block) bool {
+		if !f(block) {
+			return false
+		}
+		switch v := block.(type) {
+		case *Paragraph:
+			for _, inline := range v.ParseInlines(referenceDefinitions) {
+				InspectInline(inline, func(inline Inline) bool {
+					return f(inline)
+				})
+			}
+		}
+		return true
+	})
+}
+
+// InspectBlock traverses the blocks in depth-first order, starting with block. If f returns true,
+// InspectBlock invokes f recursively for each child of the block, followed by a call of f(nil).
+func InspectBlock(block Block, f func(Block) bool) {
+	if !f(block) {
+		return
+	}
+	switch v := block.(type) {
+	case *Document:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	case *List:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	case *ListItem:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	case *BlockQuote:
+		for _, child := range v.Children {
+			InspectBlock(child, f)
+		}
+	}
+	f(nil)
+}
+
+// InspectInline traverses the blocks in depth-first order, starting with block. If f returns true,
+// InspectInline invokes f recursively for each child of the block, followed by a call of f(nil).
+func InspectInline(inline Inline, f func(Inline) bool) {
+	if !f(inline) {
+		return
+	}
+	switch v := inline.(type) {
+	case *InlineImage:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	case *InlineLink:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	case *ReferenceImage:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	case *ReferenceLink:
+		for _, child := range v.Children {
+			InspectInline(child, f)
+		}
+	}
+	f(nil)
+}
diff --git a/utils/markdown/inspect_test.go b/utils/markdown/inspect_test.go
new file mode 100644
index 000000000..0c5032f2d
--- /dev/null
+++ b/utils/markdown/inspect_test.go
@@ -0,0 +1,54 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestInspect(t *testing.T) {
+	markdown := `
+[foo]: bar
+- a
+  > [![]()]()
+  > [![foo]][foo]
+- d
+`
+
+	visited := []string{}
+	level := 0
+	Inspect(markdown, func(blockOrInline interface{}) bool {
+		if blockOrInline == nil {
+			level--
+		} else {
+			visited = append(visited, strings.Repeat(" ", level*4)+strings.TrimPrefix(fmt.Sprintf("%T", blockOrInline), "*markdown."))
+			level++
+		}
+		return true
+	})
+
+	assert.Equal(t, []string{
+		"Document",
+		"    Paragraph",
+		"    List",
+		"        ListItem",
+		"            Paragraph",
+		"                Text",
+		"            BlockQuote",
+		"                Paragraph",
+		"                    InlineLink",
+		"                        InlineImage",
+		"                    SoftLineBreak",
+		"                    ReferenceLink",
+		"                        ReferenceImage",
+		"                            Text",
+		"        ListItem",
+		"            Paragraph",
+		"                Text",
+	}, visited)
+}
diff --git a/utils/markdown/lines.go b/utils/markdown/lines.go
new file mode 100644
index 000000000..a38b5164c
--- /dev/null
+++ b/utils/markdown/lines.go
@@ -0,0 +1,27 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+type Line struct {
+	Range
+}
+
+func ParseLines(markdown string) (lines []Line) {
+	lineStartPosition := 0
+	isAfterCarriageReturn := false
+	for position, r := range markdown {
+		if r == '\n' {
+			lines = append(lines, Line{Range{lineStartPosition, position + 1}})
+			lineStartPosition = position + 1
+		} else if isAfterCarriageReturn {
+			lines = append(lines, Line{Range{lineStartPosition, position}})
+			lineStartPosition = position
+		}
+		isAfterCarriageReturn = r == '\r'
+	}
+	if lineStartPosition < len(markdown) {
+		lines = append(lines, Line{Range{lineStartPosition, len(markdown)}})
+	}
+	return
+}
diff --git a/utils/markdown/lines_test.go b/utils/markdown/lines_test.go
new file mode 100644
index 000000000..78603c5ea
--- /dev/null
+++ b/utils/markdown/lines_test.go
@@ -0,0 +1,36 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseLines(t *testing.T) {
+	assert.Equal(t, []Line{
+		{Range{0, 4}}, {Range{4, 7}},
+	}, ParseLines("foo\nbar"))
+
+	assert.Equal(t, []Line{
+		{Range{0, 5}}, {Range{5, 8}},
+	}, ParseLines("foo\r\nbar"))
+
+	assert.Equal(t, []Line{
+		{Range{0, 4}}, {Range{4, 6}}, {Range{6, 9}},
+	}, ParseLines("foo\r\r\nbar"))
+
+	assert.Equal(t, []Line{
+		{Range{0, 4}},
+	}, ParseLines("foo\n"))
+
+	assert.Equal(t, []Line{
+		{Range{0, 4}},
+	}, ParseLines("foo\r"))
+
+	assert.Equal(t, []Line{
+		{Range{0, 5}},
+	}, ParseLines("foo\r\n"))
+}
diff --git a/utils/markdown/links.go b/utils/markdown/links.go
new file mode 100644
index 000000000..419797cb9
--- /dev/null
+++ b/utils/markdown/links.go
@@ -0,0 +1,130 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"unicode/utf8"
+)
+
+func parseLinkDestination(markdown string, position int) (raw Range, next int, ok bool) {
+	if position >= len(markdown) {
+		return
+	}
+
+	if markdown[position] == '<' {
+		isEscaped := false
+
+		for offset, c := range []byte(markdown[position+1:]) {
+			if isEscaped {
+				isEscaped = false
+				if isEscapableByte(c) {
+					continue
+				}
+			}
+
+			if c == '\\' {
+				isEscaped = true
+			} else if c == '<' {
+				break
+			} else if c == '>' {
+				return Range{position + 1, position + 1 + offset}, position + 1 + offset + 1, true
+			} else if isWhitespaceByte(c) {
+				break
+			}
+		}
+	}
+
+	openCount := 0
+	isEscaped := false
+	for offset, c := range []byte(markdown[position:]) {
+		if isEscaped {
+			isEscaped = false
+			if isEscapableByte(c) {
+				continue
+			}
+		}
+
+		switch c {
+		case '\\':
+			isEscaped = true
+		case '(':
+			openCount++
+		case ')':
+			if openCount < 1 {
+				return Range{position, position + offset}, position + offset, true
+			}
+			openCount--
+		default:
+			if isWhitespaceByte(c) {
+				return Range{position, position + offset}, position + offset, true
+			}
+		}
+	}
+	return Range{position, len(markdown)}, len(markdown), true
+}
+
+func parseLinkTitle(markdown string, position int) (raw Range, next int, ok bool) {
+	if position >= len(markdown) {
+		return
+	}
+
+	originalPosition := position
+
+	var closer byte
+	switch markdown[position] {
+	case '"', '\'':
+		closer = markdown[position]
+	case '(':
+		closer = ')'
+	default:
+		return
+	}
+	position++
+
+	for position < len(markdown) {
+		switch markdown[position] {
+		case '\\':
+			position++
+			if position < len(markdown) && isEscapableByte(markdown[position]) {
+				position++
+			}
+		case closer:
+			return Range{originalPosition + 1, position}, position + 1, true
+		default:
+			position++
+		}
+	}
+
+	return
+}
+
+func parseLinkLabel(markdown string, position int) (raw Range, next int, ok bool) {
+	if position >= len(markdown) || markdown[position] != '[' {
+		return
+	}
+
+	originalPosition := position
+	position++
+
+	for position < len(markdown) {
+		switch markdown[position] {
+		case '\\':
+			position++
+			if position < len(markdown) && isEscapableByte(markdown[position]) {
+				position++
+			}
+		case '[':
+			return
+		case ']':
+			if position-originalPosition >= 1000 && utf8.RuneCountInString(markdown[originalPosition:position]) >= 1000 {
+				return
+			}
+			return Range{originalPosition + 1, position}, position + 1, true
+		default:
+			position++
+		}
+	}
+
+	return
+}
diff --git a/utils/markdown/list.go b/utils/markdown/list.go
new file mode 100644
index 000000000..aea71156c
--- /dev/null
+++ b/utils/markdown/list.go
@@ -0,0 +1,220 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type ListItem struct {
+	blockBase
+	markdown                    string
+	hasTrailingBlankLine        bool
+	hasBlankLineBetweenChildren bool
+
+	Indentation int
+	Children    []Block
+}
+
+func (b *ListItem) Continuation(indentation int, r Range) *continuation {
+	s := b.markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		if b.Children == nil {
+			return nil
+		}
+		return &continuation{
+			Remaining: r,
+		}
+	}
+	if indentation < b.Indentation {
+		return nil
+	}
+	return &continuation{
+		Indentation: indentation - b.Indentation,
+		Remaining:   r,
+	}
+}
+
+func (b *ListItem) AddChild(openBlocks []Block) []Block {
+	b.Children = append(b.Children, openBlocks[0])
+	if b.hasTrailingBlankLine {
+		b.hasBlankLineBetweenChildren = true
+	}
+	b.hasTrailingBlankLine = false
+	return openBlocks
+}
+
+func (b *ListItem) AddLine(indentation int, r Range) bool {
+	isBlank := strings.TrimSpace(b.markdown[r.Position:r.End]) == ""
+	if isBlank {
+		b.hasTrailingBlankLine = true
+	}
+	return false
+}
+
+func (b *ListItem) HasTrailingBlankLine() bool {
+	return b.hasTrailingBlankLine || (len(b.Children) > 0 && b.Children[len(b.Children)-1].HasTrailingBlankLine())
+}
+
+func (b *ListItem) isLoose() bool {
+	if b.hasBlankLineBetweenChildren {
+		return true
+	}
+	for i, child := range b.Children {
+		if i < len(b.Children)-1 && child.HasTrailingBlankLine() {
+			return true
+		}
+	}
+	return false
+}
+
+type List struct {
+	blockBase
+	markdown                    string
+	hasTrailingBlankLine        bool
+	hasBlankLineBetweenChildren bool
+
+	IsLoose           bool
+	IsOrdered         bool
+	OrderedStart      int
+	BulletOrDelimiter byte
+	Children          []*ListItem
+}
+
+func (b *List) Continuation(indentation int, r Range) *continuation {
+	s := b.markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		return &continuation{
+			Remaining: r,
+		}
+	}
+	return &continuation{
+		Indentation: indentation,
+		Remaining:   r,
+	}
+}
+
+func (b *List) AddChild(openBlocks []Block) []Block {
+	if item, ok := openBlocks[0].(*ListItem); ok {
+		b.Children = append(b.Children, item)
+		if b.hasTrailingBlankLine {
+			b.hasBlankLineBetweenChildren = true
+		}
+		b.hasTrailingBlankLine = false
+		return openBlocks
+	} else if list, ok := openBlocks[0].(*List); ok {
+		if len(list.Children) == 1 && list.IsOrdered == b.IsOrdered && list.BulletOrDelimiter == b.BulletOrDelimiter {
+			return b.AddChild(openBlocks[1:])
+		}
+	}
+	return nil
+}
+
+func (b *List) AddLine(indentation int, r Range) bool {
+	isBlank := strings.TrimSpace(b.markdown[r.Position:r.End]) == ""
+	if isBlank {
+		b.hasTrailingBlankLine = true
+	}
+	return false
+}
+
+func (b *List) HasTrailingBlankLine() bool {
+	return b.hasTrailingBlankLine || (len(b.Children) > 0 && b.Children[len(b.Children)-1].HasTrailingBlankLine())
+}
+
+func (b *List) isLoose() bool {
+	if b.hasBlankLineBetweenChildren {
+		return true
+	}
+	for i, child := range b.Children {
+		if child.isLoose() || (i < len(b.Children)-1 && child.HasTrailingBlankLine()) {
+			return true
+		}
+	}
+	return false
+}
+
+func (b *List) Close() {
+	b.IsLoose = b.isLoose()
+}
+
+func parseListMarker(markdown string, r Range) (success, isOrdered bool, orderedStart int, bulletOrDelimiter byte, markerWidth int, remaining Range) {
+	digits := 0
+	n := 0
+	for i := r.Position; i < r.End && markdown[i] >= '0' && markdown[i] <= '9'; i++ {
+		digits++
+		n = n*10 + int(markdown[i]-'0')
+	}
+	if digits > 0 {
+		if digits > 9 || r.Position+digits >= r.End {
+			return
+		}
+		next := markdown[r.Position+digits]
+		if next != '.' && next != ')' {
+			return
+		}
+		return true, true, n, next, digits + 1, Range{r.Position + digits + 1, r.End}
+	}
+	if r.Position >= r.End {
+		return
+	}
+	next := markdown[r.Position]
+	if next != '-' && next != '+' && next != '*' {
+		return
+	}
+	return true, false, 0, next, 1, Range{r.Position + 1, r.End}
+}
+
+func listStart(markdown string, indent int, r Range, matchedBlocks, unmatchedBlocks []Block) []Block {
+	afterList := false
+	if len(matchedBlocks) > 0 {
+		_, afterList = matchedBlocks[len(matchedBlocks)-1].(*List)
+	}
+	if !afterList && indent > 3 {
+		return nil
+	}
+
+	success, isOrdered, orderedStart, bulletOrDelimiter, markerWidth, remaining := parseListMarker(markdown, r)
+	if !success {
+		return nil
+	}
+
+	isBlank := strings.TrimSpace(markdown[remaining.Position:remaining.End]) == ""
+	if len(matchedBlocks) > 0 && len(unmatchedBlocks) == 0 {
+		if _, ok := matchedBlocks[len(matchedBlocks)-1].(*Paragraph); ok {
+			if isBlank || (isOrdered && orderedStart != 1) {
+				return nil
+			}
+		}
+	}
+
+	indentAfterMarker, indentBytesAfterMarker := countIndentation(markdown, remaining)
+	if !isBlank && indentAfterMarker < 1 {
+		return nil
+	}
+
+	remaining = Range{remaining.Position + indentBytesAfterMarker, remaining.End}
+	consumedIndentAfterMarker := indentAfterMarker
+	if isBlank || indentAfterMarker >= 5 {
+		consumedIndentAfterMarker = 1
+	}
+
+	listItem := &ListItem{
+		markdown:    markdown,
+		Indentation: indent + markerWidth + consumedIndentAfterMarker,
+	}
+	list := &List{
+		markdown:          markdown,
+		IsOrdered:         isOrdered,
+		OrderedStart:      orderedStart,
+		BulletOrDelimiter: bulletOrDelimiter,
+		Children:          []*ListItem{listItem},
+	}
+	ret := []Block{list, listItem}
+	if descendants := blockStartOrParagraph(markdown, indentAfterMarker-consumedIndentAfterMarker, remaining, nil, nil); descendants != nil {
+		listItem.Children = append(listItem.Children, descendants[0])
+		ret = append(ret, descendants...)
+	}
+	return ret
+}
diff --git a/utils/markdown/markdown.go b/utils/markdown/markdown.go
new file mode 100644
index 000000000..3061ba4bb
--- /dev/null
+++ b/utils/markdown/markdown.go
@@ -0,0 +1,132 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+// This package implements a parser for the subset of the CommonMark spec necessary for us to do
+// server-side processing. It is not a full implementation and lacks many features. But it is
+// complete enough to efficiently and accurately allow us to do what we need to like rewrite image
+// URLs for proxying.
+package markdown
+
+import (
+	"strings"
+)
+
+func isEscapable(c rune) bool {
+	return c > ' ' && (c < '0' || (c > '9' && (c < 'A' || (c > 'Z' && (c < 'a' || (c > 'z' && c <= '~'))))))
+}
+
+func isEscapableByte(c byte) bool {
+	return isEscapable(rune(c))
+}
+
+func isWhitespace(c rune) bool {
+	switch c {
+	case ' ', '\t', '\n', '\u000b', '\u000c', '\r':
+		return true
+	default:
+		return false
+	}
+}
+
+func isWhitespaceByte(c byte) bool {
+	return isWhitespace(rune(c))
+}
+
+func isHex(c rune) bool {
+	return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')
+}
+
+func isHexByte(c byte) bool {
+	return isHex(rune(c))
+}
+
+func nextNonWhitespace(markdown string, position int) int {
+	for offset, c := range []byte(markdown[position:]) {
+		if !isWhitespaceByte(c) {
+			return position + offset
+		}
+	}
+	return len(markdown)
+}
+
+func nextLine(markdown string, position int) (linePosition int, skippedNonWhitespace bool) {
+	for i := position; i < len(markdown); i++ {
+		c := markdown[i]
+		if c == '\r' {
+			if i+1 < len(markdown) && markdown[i+1] == '\n' {
+				return i + 2, skippedNonWhitespace
+			}
+			return i + 1, skippedNonWhitespace
+		} else if c == '\n' {
+			return i + 1, skippedNonWhitespace
+		} else if !isWhitespaceByte(c) {
+			skippedNonWhitespace = true
+		}
+	}
+	return len(markdown), skippedNonWhitespace
+}
+
+func countIndentation(markdown string, r Range) (spaces, bytes int) {
+	for i := r.Position; i < r.End; i++ {
+		if markdown[i] == ' ' {
+			spaces++
+			bytes++
+		} else if markdown[i] == '\t' {
+			spaces += 4
+			bytes++
+		} else {
+			break
+		}
+	}
+	return
+}
+
+func trimLeftSpace(markdown string, r Range) Range {
+	s := markdown[r.Position:r.End]
+	trimmed := strings.TrimLeftFunc(s, isWhitespace)
+	return Range{r.Position, r.End - (len(s) - len(trimmed))}
+}
+
+func trimRightSpace(markdown string, r Range) Range {
+	s := markdown[r.Position:r.End]
+	trimmed := strings.TrimRightFunc(s, isWhitespace)
+	return Range{r.Position, r.End - (len(s) - len(trimmed))}
+}
+
+func relativeToAbsolutePosition(ranges []Range, position int) int {
+	rem := position
+	for _, r := range ranges {
+		l := r.End - r.Position
+		if rem < l {
+			return r.Position + rem
+		}
+		rem -= l
+	}
+	if len(ranges) == 0 {
+		return 0
+	}
+	return ranges[len(ranges)-1].End
+}
+
+func trimBytesFromRanges(ranges []Range, bytes int) (result []Range) {
+	rem := bytes
+	for _, r := range ranges {
+		if rem == 0 {
+			result = append(result, r)
+			continue
+		}
+		l := r.End - r.Position
+		if rem < l {
+			result = append(result, Range{r.Position + rem, r.End})
+			rem = 0
+			continue
+		}
+		rem -= l
+	}
+	return
+}
+
+func Parse(markdown string) (*Document, []*ReferenceDefinition) {
+	lines := ParseLines(markdown)
+	return ParseBlocks(markdown, lines)
+}
diff --git a/utils/markdown/paragraph.go b/utils/markdown/paragraph.go
new file mode 100644
index 000000000..6a40fdf89
--- /dev/null
+++ b/utils/markdown/paragraph.go
@@ -0,0 +1,71 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+)
+
+type Paragraph struct {
+	blockBase
+	markdown string
+
+	Text                 []Range
+	ReferenceDefinitions []*ReferenceDefinition
+}
+
+func (b *Paragraph) ParseInlines(referenceDefinitions []*ReferenceDefinition) []Inline {
+	return ParseInlines(b.markdown, b.Text, referenceDefinitions)
+}
+
+func (b *Paragraph) Continuation(indentation int, r Range) *continuation {
+	s := b.markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		return nil
+	}
+	return &continuation{
+		Indentation: indentation,
+		Remaining:   r,
+	}
+}
+
+func (b *Paragraph) Close() {
+	for {
+		for i := 0; i < len(b.Text); i++ {
+			b.Text[i] = trimLeftSpace(b.markdown, b.Text[i])
+			if b.Text[i].Position < b.Text[i].End {
+				break
+			}
+		}
+
+		if len(b.Text) == 0 || b.Text[0].Position < b.Text[0].End && b.markdown[b.Text[0].Position] != '[' {
+			break
+		}
+
+		definition, remaining := parseReferenceDefinition(b.markdown, b.Text)
+		if definition == nil {
+			break
+		}
+		b.ReferenceDefinitions = append(b.ReferenceDefinitions, definition)
+		b.Text = remaining
+	}
+
+	for i := len(b.Text) - 1; i >= 0; i-- {
+		b.Text[i] = trimRightSpace(b.markdown, b.Text[i])
+		if b.Text[i].Position < b.Text[i].End {
+			break
+		}
+	}
+}
+
+func newParagraph(markdown string, r Range) *Paragraph {
+	s := markdown[r.Position:r.End]
+	if strings.TrimSpace(s) == "" {
+		return nil
+	}
+	return &Paragraph{
+		markdown: markdown,
+		Text:     []Range{r},
+	}
+}
diff --git a/utils/markdown/reference_definition.go b/utils/markdown/reference_definition.go
new file mode 100644
index 000000000..e2d0be350
--- /dev/null
+++ b/utils/markdown/reference_definition.go
@@ -0,0 +1,75 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package markdown
+
+type ReferenceDefinition struct {
+	RawDestination Range
+
+	markdown string
+	rawLabel string
+	rawTitle string
+}
+
+func (d *ReferenceDefinition) Destination() string {
+	return Unescape(d.markdown[d.RawDestination.Position:d.RawDestination.End])
+}
+
+func (d *ReferenceDefinition) Label() string {
+	return d.rawLabel
+}
+
+func (d *ReferenceDefinition) Title() string {
+	return Unescape(d.rawTitle)
+}
+
+func parseReferenceDefinition(markdown string, ranges []Range) (*ReferenceDefinition, []Range) {
+	raw := ""
+	for _, r := range ranges {
+		raw += markdown[r.Position:r.End]
+	}
+
+	label, next, ok := parseLinkLabel(raw, 0)
+	if !ok {
+		return nil, nil
+	}
+	position := next
+
+	if position >= len(raw) || raw[position] != ':' {
+		return nil, nil
+	}
+	position++
+
+	destination, next, ok := parseLinkDestination(raw, nextNonWhitespace(raw, position))
+	if !ok {
+		return nil, nil
+	}
+	position = next
+
+	absoluteDestination := relativeToAbsolutePosition(ranges, destination.Position)
+	ret := &ReferenceDefinition{
+		RawDestination: Range{absoluteDestination, absoluteDestination + destination.End - destination.Position},
+		markdown:       markdown,
+		rawLabel:       raw[label.Position:label.End],
+	}
+
+	if position < len(raw) && isWhitespaceByte(raw[position]) {
+		title, next, ok := parseLinkTitle(raw, nextNonWhitespace(raw, position))
+		if !ok {
+			if nextLine, skippedNonWhitespace := nextLine(raw, position); !skippedNonWhitespace {
+				return ret, trimBytesFromRanges(ranges, nextLine)
+			}
+			return nil, nil
+		}
+		if nextLine, skippedNonWhitespace := nextLine(raw, next); !skippedNonWhitespace {
+			ret.rawTitle = raw[title.Position:title.End]
+			return ret, trimBytesFromRanges(ranges, nextLine)
+		}
+	}
+
+	if nextLine, skippedNonWhitespace := nextLine(raw, position); !skippedNonWhitespace {
+		return ret, trimBytesFromRanges(ranges, nextLine)
+	}
+
+	return nil, nil
+}