diff --git a/help/opers/cmode b/help/opers/cmode
index 97cbbd8d1..3383ed55b 100644
--- a/help/opers/cmode
+++ b/help/opers/cmode
@@ -1,5 +1,8 @@
 MODE <channel> <+|-><modes> [parameters]
 
+? designates that the cmode is provided by an extension
+and may not be present on this server.
+ 
 CHANNELMODE - DESCRIPTION
 ------------------------------------------------------------------------
 NO PARAMETERS:
@@ -29,6 +32,11 @@ NO PARAMETERS:
               (however, new forwards can still be set subject to +F).
      +C     - Disable CTCP. All CTCP messages to the channel, except ACTION,
               are disallowed.
+  ?  +O     - IRC Operator only channel.
+  ?  +A     - IRC server administrator only channel.
+  ?  +T     - No NOTICEs allowed in the channel.
+  ?  +S     - Only users connected via SSL/TLS may join the channel while this 
+              mode is set. Users already in the channel are not affected.
 
 WITH PARAMETERS:
      +f     - Forward.  Forwards users who cannot join because of +i,