Channel Modes

Example

To set +c on the channel #help:

/mode #help +c

To unset it:

/mode #help -c

Channel Modes

Flag	Title	Description
Modes that prevent certain messages
c	No control codes	Prevent any users from sending colored, underlined and bold text unless they are voiced or have higher user modes in the channel. Does not affect CTCP or ISO-2022 (unicode).
C	No CTCPs	Prevent any user without voice (+v) or higher from sending CTCPs to the channel. Exception: CTCP ACTION (/me) and CTCP DCC (/dcc send) are still permitted.
n	No external messages	Prevent users not in the channel from using /msg #channel.
m	Moderated	Prevent users without voice (+v) or higher from talking in the channel.
M	ModReg	Prevent unregistered users without voice (+v) or higher from talking in the channel. (Also see mode +R.)
N	No notices	Prevent users without voice (+v) or higher from sending channel notices through /notice
Modes that prevent certain users from joining
i	Invite only	Prevent users from joining the channel unless they have received an invitation from someone inside with /invite nick, or they match an entry on the +I list
R	Registered only	Prevent unregistered users from joining the channel. (Also see mode +M.)
S	SSL only	Prevent non-SSL users from joining the channel.
O	Oper only	Only IRC Operators may set this mode. Prevent non-opers from joining the channel.
Other modes
t	Ops topic	Prevent any user who does not have halfop or higher to set channel topics.
s	Secret	Make the channel completely secret to anyone (except server admins). With this mode set, the channel will not be shown in /whois or /list.
p	Paranoia	Prevents users with halfop from kicking each other or giving/removing other halfops. Disables /knocks if the channel is locked with +i, +k or +l mode. A channel notice will be shown when a user is invited. Prevent users that are not halfop or higher from inviting users to the channel.
B	Bandwidth saver	Prevent anyone set /away or anyone who has idled for more than 30 minutes from reading what is being said in the channel. When the idle time is broke, they are able to read new messages in the channel again like normal users.
z	Persist	Only Services may set this mode. Set by default when you register a channel. Prevent channel modes from being reset when the last user leaves a registered channel.

Channel Modes Involving a Parameter

Flag	Title	Description
Modes that prevent or allow certain users from joining
k	Key	This is what most would refer as a 'channel password'. It'll prevent users without the channel key to join it. If you have the password, you can join it with /join #channel key. To set this mode: /mode #channel +k key
l	Limit	If you have this set to a certain number, people will not be able to join the channel if the user count reaches the limit. /mode #channel +l limit.
b	Ban	This will prevent a user from entering the channel, based on a nick!ident@host match. Alternatively, if the user is already in the channel, this mode will mute them if they have no status. /mode #channel +b nick!ident@host Examples: /mode #help +b Peter!*@* will ban all users using the nick Peter. /mode #help +b *!*@*.br will ban all of Brazil and everyone connected from the country.
e	Exempt	This will allow a user to join a channel even if they are banned (+b), based on a nick!ident@host match. /mode #channel +eeee n!u@h1 n!u@h2 n!u@h3 n!u@h4 Examples: /mode #help +e Joe!*@* will allow 'Joe' to join the channel even if he is banned. /mode #help +e *!*@*.com will allow anyone connecting through a host ending on .com to join the channel for the same reasons as Joe.
I	Invite Exempt	This will allow a user to join an invite-only (+i) channel, based on a nick!user@host match. /mode #channel +IIII n!u@h1 n!u@h2 n!u@h3 n!u@h4 Examples: /mode #help +I Bob!*@* will allow 'Bob' to join the invite-only channel even if no one has sent him an invite /mode #help +I *!*@*.net will allow anyone connecting through a host ending on .net to join the channel for the same reasons as Bob.
Modes that give users extra abilities
v	Voice	By giving this user mode to someone, you will allow them to talk if the channel is muted through CMODE +m. /mode #channel +vvvv nick1 nick2 nick3 nick4
h	Half-op	This will allow a user to set most of the channel modes and they will be able to kick users who have voice (+v) or nothing in the channel. However, they are unable to kick each other if CMODE +p is set. Half-ops are unable to kick +o users (and higher) regardless of channel modes. /mode #channel +hhhh nick1 nick2 nick3 nick4
o	Op	This gives the user control over half-opped, voiced, and regular users. An opped user may op other users, set any mode except +q and +a, and remove ops from whoever they want. Opped users cannot perform actions against owners, or protected users. /mode #channel +oooo nick1 nick2 nick3 nick4
a	Protected/Admin	This gives the user control over opped, half-opped, voiced, and regular users. A protected/admin user may op other users, set any mode except +q and +a, and remove ops from whoever they want. Protected/admin users cannot perform actions against owners or other protected users. /mode #channel +aaaa nick1 nick2 nick3 nick4
q	Owner	This gives the user full control over the channel. An owner may owner/protect/op other users, set any mode, and remove owner/protect/ops from whoever they want. /mode #channel +qqqq nick1 nick2 nick3 nick4