diff --git a/changelogs/client_server/newsfragments/1397.feature b/changelogs/client_server/newsfragments/1397.feature
new file mode 100644
index 00000000..e4bd248a
--- /dev/null
+++ b/changelogs/client_server/newsfragments/1397.feature
@@ -0,0 +1 @@
+Document message formats on ``m.text`` and ``m.emote`` messages
diff --git a/event-schemas/examples/m.room.message#m.emote b/event-schemas/examples/m.room.message#m.emote
index 4280928e..79292ddf 100644
--- a/event-schemas/examples/m.room.message#m.emote
+++ b/event-schemas/examples/m.room.message#m.emote
@@ -2,7 +2,9 @@
   "age": 242352,
   "content": {
     "body": "thinks this is an example emote",
-    "msgtype": "m.emote"
+    "msgtype": "m.emote",
+    "format": "org.matrix.custom.html",
+    "formatted_body": "thinks <b>this</b> is an example emote"
   },
   "origin_server_ts": 1431961217939,
   "event_id": "$WLGTSEFSEF:localhost",
diff --git a/event-schemas/examples/m.room.message#m.text b/event-schemas/examples/m.room.message#m.text
index e00c7aa5..48a97db8 100644
--- a/event-schemas/examples/m.room.message#m.text
+++ b/event-schemas/examples/m.room.message#m.text
@@ -2,7 +2,9 @@
   "age": 242352,
   "content": {
     "body": "This is an example text message",
-    "msgtype": "m.text"
+    "msgtype": "m.text",
+    "format": "org.matrix.custom.html",
+    "formatted_body": "<b>This is an example text message</b>"
   },
   "origin_server_ts": 1431961217939,
   "event_id": "$WLGTSEFSEF:localhost",
diff --git a/event-schemas/schema/m.room.message#m.emote b/event-schemas/schema/m.room.message#m.emote
index 88860cb2..f67a184b 100644
--- a/event-schemas/schema/m.room.message#m.emote
+++ b/event-schemas/schema/m.room.message#m.emote
@@ -12,6 +12,16 @@ properties:
         enum:
           - m.emote
         type: string
+      format:
+        description: |-
+          The format used in the ``formatted_body``. Currently only
+          ``org.matrix.custom.html`` is supported.
+        type: string
+      formatted_body:
+        description: |-
+          The formatted version of the ``body``. This is required if ``format``
+          is specified.
+        type: string
     required:
       - msgtype
       - body
diff --git a/event-schemas/schema/m.room.message#m.text b/event-schemas/schema/m.room.message#m.text
index 2720172d..b481bcea 100644
--- a/event-schemas/schema/m.room.message#m.text
+++ b/event-schemas/schema/m.room.message#m.text
@@ -12,6 +12,16 @@ properties:
         enum:
           - m.text
         type: string
+      format:
+        description: |-
+          The format used in the ``formatted_body``. Currently only
+          ``org.matrix.custom.html`` is supported.
+        type: string
+      formatted_body:
+        description: |-
+          The formatted version of the ``body``. This is required if ``format``
+          is specified.
+        type: string
     required:
       - msgtype
       - body