diff --git a/TODO b/TODO
index 4b75c8517da..dd432b07af8 100644
--- a/TODO
+++ b/TODO
@@ -163,7 +163,6 @@ Features:
   - Document word splitting syntax for ExecStart= and friends
   - document that units from /etc override those from /usr and /run
   - document the exit codes when services fail before they are exec()ed
-  - document that %% can be used to write % in a string that is specifier extended
   - document that service reload may be implemented as service reexec
   - document in wiki how to map ical recurrence events to systemd timer unit calendar specifications
 
diff --git a/man/systemd.unit.xml.in b/man/systemd.unit.xml.in
index 43f5ffc1f26..e99703f7b32 100644
--- a/man/systemd.unit.xml.in
+++ b/man/systemd.unit.xml.in
@@ -1287,6 +1287,11 @@
                         <entry>Host name</entry>
                         <entry>The host name of the running system.</entry>
                       </row>
+                      <row>
+                        <entry><literal>%%</literal></entry>
+                        <entry>Escaped %</entry>
+                        <entry>Single percent sign.</entry>
+                      </row>
                     </tbody>
                   </tgroup>
                 </table>