diff --git a/src/docs/user/userguide/differential.diviner b/src/docs/user/userguide/differential.diviner
--- a/src/docs/user/userguide/differential.diviner
+++ b/src/docs/user/userguide/differential.diviner
@@ -66,6 +66,7 @@
   - diving into the details of inline comments in
     @{article:Differential User Guide: Inline Comments}; or
   - reading the FAQ at @{article:Differential User Guide: FAQ}; or
+  - learning how to use markup in comments at @{article:Remarkup Reference}; or
   - learning about test plans in
     @{article:Differential User Guide: Test Plans}; or
   - learning more about Herald in @{article:Herald User Guide}.
diff --git a/src/docs/user/userguide/differential_faq.diviner b/src/docs/user/userguide/differential_faq.diviner
--- a/src/docs/user/userguide/differential_faq.diviner
+++ b/src/docs/user/userguide/differential_faq.diviner
@@ -41,8 +41,9 @@
 
 If authors are being jerks about this (making sweeping changes as soon as they
 get an accept), solve the problem socially by telling them to stop being jerks.
-Unless you've configured additional layers of enforcement, there's nothing
-stopping them from silently changing the code before pushing it, anyway.
+Unless you've configured additional layers of enforcement (by
+using @{article:Herald}), there's nothing stopping them from silently changing
+the code before pushing it, anyway.
 
 
 = How can I enable syntax highlighting? =
@@ -50,6 +51,10 @@
 You need to install and configure **Pygments** to highlight anything else than
 PHP. See the `pygments.enabled` configuration setting.
 
+= What formatting can  be used in comments? =
+
+Phabricator implements a markup language similar to Markdown.
+See @{article:Remarkup Reference}
 
 = What do the very light green and red backgrounds mean? =
 
diff --git a/src/docs/user/userguide/remarkup.diviner b/src/docs/user/userguide/remarkup.diviner
--- a/src/docs/user/userguide/remarkup.diviner
+++ b/src/docs/user/userguide/remarkup.diviner
@@ -732,3 +732,7 @@
 Remarkup editors provide a fullscreen composition mode. This can make it easier
 to edit large blocks of text, or improve focus by removing distractions. You can
 exit **Fullscreen** mode by clicking the button again or by pressing escape.
+
+See Also
+========
+* @{article:Remarkup Reference: Cowsay}
diff --git a/src/docs/user/userguide/remarkup_cowsay.diviner b/src/docs/user/userguide/remarkup_cowsay.diviner
new file mode 100644
--- /dev/null
+++ b/src/docs/user/userguide/remarkup_cowsay.diviner
@@ -0,0 +1,57 @@
+@title Remarkup Reference: Cowsay
+@group userguide
+
+Overview
+--------
+
+Cowsay is an application by Tony Monroe which has been ported over to
+Phabricator/Phorge to allow your comments to be voiced by
+a cow.
+
+Basic Usage
+-----------
+
+A basic example of using cowsay would be to add a comment
+  cowsay{{{Great work!}}}
+which generates:
+```
+ _____________
+< Great work! >
+ -------------
+        \   ^__^
+         \  (oo)\_______
+            (__)\       )\/\
+                ||----w |
+                ||     ||
+```
+
+Other Cowsay Templates
+----------------------
+Other templates are available in externals/cowsay/cows/, and you can specify
+one by calling cowsay with the 'cow' parameter. eg:
+  cowsay(cow='tux'){{{Great work!}}}
+generates
+```
+ _____________
+< Great work! >
+ -------------
+   \
+    \
+        .--.
+       |o_o |
+       |:_/ |
+      //   \ \
+     (|     | )
+    /'\_   _/`\
+    \___)=(___/
+```
+
+Other Parameters
+----------------
+* think (set to 1 for thinking bubbles)
+* eyes (default 'oo')
+* tongue (default '  ', try 'P')
+
+See Also
+========
+* @{article:Remarkup Reference}