(however, new forwards can still be set subject to +F).
+C - Disable CTCP. All CTCP messages to the channel, except ACTION,
are disallowed.
+ +S - This ensures only users that have connected via TLS/SSL (and
+ so have user mode +Z) are able to join; you can not /invite
+ them through it. It will not prevent the use of the channel
+ by any non-TLS/SSL users already present.
WITH PARAMETERS:
+f - Forward. Forwards users who cannot join because of +i,