diff --git a/common/locale/en-US/index.xml b/common/locale/en-US/index.xml
index 8053e627..f451df93 100644
--- a/common/locale/en-US/index.xml
+++ b/common/locale/en-US/index.xml
@@ -18,6 +18,7 @@ This file contains a list of all available commands, mappings and options.
 <dl>
     <dt><k mode="i">i</k></dt> <dd>Start Insert mode in text areas when <o>insertmode</o> is not set</dd>
     <dt><k name="C-i" mode="i"/></dt> <dd>Launch the external editor</dd>
+    <dt><k name="C-t" mode="i"/></dt> <dd>Enter Textarea mode</dd>
     <dt><k name="C-]" mode="i"/></dt> <dd>Expand an Insert-mode abbreviation</dd>
 </dl>
 
diff --git a/common/locale/en-US/insert.xml b/common/locale/en-US/insert.xml
index bba5b00e..b727c561 100644
--- a/common/locale/en-US/insert.xml
+++ b/common/locale/en-US/insert.xml
@@ -39,6 +39,16 @@
     </description>
 </item>
 
+<item>
+    <tags><![CDATA[i_<C-t>]]></tags>
+    <spec>&lt;C-t></spec>
+    <description short="true">
+        <p>
+            Enter Textarea mode. This is useful for quick editing of text fields
+            with basic Vim-keys support. See also <o>insertmode</o>.
+        </p>
+    </description>
+</item>
 
 <item>
     <tags><![CDATA[i_<C-]>]]></tags>
diff --git a/common/locale/en-US/options.xml b/common/locale/en-US/options.xml
index bc1950dd..6a79af01 100644
--- a/common/locale/en-US/options.xml
+++ b/common/locale/en-US/options.xml
@@ -829,8 +829,7 @@
         </p>
 
         <p>
-            Textarea mode can be entered with <k name="C-t"/> from Insert mode.
-            <!-- TODO: <C-t> is not documented yet. -->
+            Textarea mode can be entered with <k name="C-t" mode="i"/> from Insert mode.
         </p>
     </description>
 </item>
diff --git a/pentadactyl/TODO b/pentadactyl/TODO
index 2452855b..a1f9ad41 100644
--- a/pentadactyl/TODO
+++ b/pentadactyl/TODO
@@ -37,7 +37,7 @@ FEATURES:
 9 Fix the arbitrary distinction between 'hinttags' and
   'extendedhinttags'
 9 Support multiple bookmarks, -keyword, -tags in :delbmarks
-8 Document Textarea, Caret and Visual modes.
+8 Document Caret and Visual modes.
 8 finish :help TODOs
 8 fix local options
 8 adaptive timeout for auto-completions, :set completions can be updated more often than