Channel Modes

Revision 1.20

Red denotes a conflicting numeric definition, gray for deprecated (however quite possibly still in use), and blue for OK.

Mode Name Origin Server On Server Off Parameter Comments
a ANONYMOUS RFC2811 Marks the channel to use anonymous conversations. All conversations, and people joining/parting are viewed all from 'anonymous!anonymous@anonymous'. Users quitting are seen as users parting the channel with no reason.
a HIDEOPS Hybrid Anonymous operators - channel operators a hidden
a CHANNEL_PROTECTION Unreal Nickname Gives the given nickname 'protection'; Cannot be kicked/deopped
A ADMIN_ONLY Unreal Only server/service/network (co-)administrators can join the channel
A ALLOW_INVITE InspIRCd Allow everyone to use INVITE, even non-privileged users
b BAN RFC1459 n!u@h mask Bans the specified mask from the channel
B BLOCKCAPS InspIRCd Block messages with too many CAPITAL LETTERS.
c NOCONTROL Hybrid? Stops control codes from being broadcast from the channel.
c NOCOLOUR Bahamut Stops color from being broadcast from the channel. Some implementations drop lines, some implementations strip it.
C NO_CTCP Unreal Stops people from sending CTCP commands to the channel
d DELAYMSG InspIRCd <secs> Disallows a user from talking in the channel until they've been in there for the specified number of seconds.
d DENY Real-name Like ban, but apparently bans through matching the given one- word mask to the 'irc-name' or 'real name' field a client has.
d HAS_HIDDEN QuakeNet Y Y Set by the server when the channel mode +D (on QuakeNet) was removed, but there are still 'hidden' users in the channel
D DELAYJOINS QuakeNet When set, all joins are hidden until the user is given a voice, oper status, until they speak, or change a topic etc.
e BAN_EXCEPTION RFC2811 n!u@h mask Creates a ban exception using the given mask. Normally, if someone's identity fits a channel ban mask, they are banned. If their identity also matches the ban exception mask, they are allowed not banned (exempt from the ban)
e EVENT AustHex Stops users from changing their nicknames when set. AustNet considers this obsolete, due to the conflict between the more widely accepted use of the 'e' mode.
f FLOOD_LIMIT Unreal <lines>:<seconds> Flood limiter
f FORWARD Charybdis? <channel> Forwards users who cannot join because of +i, +j, +l or +r to the given channel.
F FREE_TARGET Charybdis? Anyone may set FORWARDs to this channel (otherwise, ops are necessary)

Also see FORWARD.
F NICKFLOOD InspIRCd <num>:<sec> Only allow nick changes per seconds, to stop spam.
g CHANFILTER InspIRCd <keyword> Blocks messages matching (including wildcards).
g FREE_INVITE Charybdis? Everyone may invite users
G STRIP_BAD_WORDS Unreal Strips profanity from messages broadcast through the channel
h HALFOP RFC2811 Nickname Gives the specified nickname channel half-operator status
H HISTORY InspIRCd <num>:<sec> When users join, show them lines or seconds of channel history, whichever is shorter.
H NO_HIDING 3rd-party Unreal When set, this stops users set umode +I (INVISIBLE_JOINPART) from being able to join or part a channel secretly. This mode was only implemented by an old and unpopular third-party Unreal module. Starting with v3.2, Unreal uses +H for HISTORY (see above)
i INVITE_ONLY RFC1459 Marks the channel as invite only. When set, clients must be invited using the INVITE command prior to being allowed to join the channel
I INVITATION_MASK RFC2811 n!u@h mask If the channel is marked as invite only, users matching the mask(s) set using this mode are allowed to enter without invitation. Also called "invite exempt"
j JOIN_THROTTLE Charybdis? <count>:<time> When set, 'count' number of users may join this channel per 'time'
J JOIN_THROTTLE Dancer <frequency>,<limit> When set, users may join this channel once every 'frequency' seconds with an initial burst and limit value of 'limit' users
J KICK_NOREJOIN InspIRCd <sec> After being KICKed, user can't rejoin for seconds.
k KEYLOCK RFC1459 Password Locks the channel with the given password, which must be specified via the JOIN command to any clients attempting to join the channel when set. The correct key must be given when turning this mode off.
K NOKNOCK Unreal Disables people using KNOCK on the channel
l LIMIT RFC1459 Integer Limits the channel to only allow the given number of members to be in the channel while the mode is set. Nobody else is allowed to join the channel while the channel membership count is greater than or equal to the number given with the mode, however some implementations allow IRC operators to circumvent that rule. Most traditional implementations accept only a signed integer here (using atoi()), however some more modern implementations may accept an unsigned integer (i.e. strtoul()), or even have machine variations on whether a 32-bit or 64-bit integer is accepted.
L LISTED Bahamut
L LINK Unreal <channel> Forwards users cannot join a channel for some reason (+b, +i, +l, +R, +z, ...), tothe given channel.
L LARGE_BANLIST Charybdis? Increase the number of +beIq entries allowed for this channel. Only settable by IRC opers
m MODERATED RFC1459 The channel is being moderated. Only users who have a voice are able to talk (people who are voiced or channel operator members)
M MODREG Bahamut Unregistered/unidentified clients cannot send text to the channel
M NOOPERKICK ircd-seven Disallows kicking an oper from the channel. Only settable by IRC opers.
M REGONLY Unreal Channel only allows registered nicknames to talk.
n NO_EXTERNAL Hybrid? Only allow users who are joined to this channel to send messages to the channel
N NO_NICK_CHANGE Unreal Disallow nickname changes. This is similar to AustHex's obsolete +e ('event') mode
o OPER RFC1459 Nickname Gives the specified nickname channel operator status
O CREATOR RFC2811 Nickname Give the specified nickname channel creator status
O OPER_ONLY Bahamut, Unreal Channel only allows IRC operators to join
p PRIVATE RFC1459 Marks the channel as private. Using this form, +p cannot be set with +s at the same time. Setting +p while +s is set turns off +s, and vice-versa. This is widely considered obsolete in favor of the secret mode (+s).
p PRIVATE Hybrid This restricts KNOCK, and prevents half-ops from using +h
p PRIVATE Charybdis? This restricts KNOCK
p PARANOIA Hybrid Controls whether half-ops may invite users into the channel or whether they can kick other members of the channel
P PERMANENT Charybdis? Channel does not disappear when empty. Only settable by IRC opers
q QUIET Charybdis? <nickmask> Prevents a user from sending to the channel or changing nick, based on a nickmask match
q QUIET RFC2811 Y Y Sets the channel to be quiet. When set, it restricts what is sent to clients who are on the channel. Joins, parts, and nick changes are not broadcast. From the user's point of view, the channel only contains one user (them).
q CHANNEL_OWNER Unreal Nickname Gives the nickname channel owner status
Q NO_KICK Unreal Disallow people being kicked from the channel
Q NO_FORWARD Charybdis? Users cannot be forwarded to this channel

Also see FORWARD.
r REGISTERED Bahamut Y Y Channel is registered with a network channel service
r REOP RFC2811 This mode is used to prevent a channel from having no operator for an extended period of time. When set, any channel that has lost all its channel operators for a certain period of time automatically has some or all channel members given channel operator status. RFC2811 specifies this is only available to '!' channels, but some implementations are reported to use it on other channel types, since they use timestamping to avoid channel take-overs during network splits.
r REGONLY ircu Channel only allows registered nicknames to join/talk.
R REGONLY Bahamut, tr-ircd Channel only allows registered nicknames to join/talk
R REGONLY Hybrid? Channel only allows registered nicknames to join

Also see MODREG.
R REOP_LIST IRCNet n!u@h mask Re-oper list - a list of identities used as a hint for reop when a channel is opless for a long enough time. Only one of the matches is used for the reop.
s SECRET RFC1459 Marks the channel as secret. The channel will not appear in channel listings, the NAMES command will not list nicknames for users who are not channel members, and the channel will not appear in WHOIS unless WHOIS is called by a fellow channel member.
S STRIP Unreal Strip formatting codes from messages sent to the channel
S SECURED_ONLY Hybrid? Only allows clients connected via secure connections to join (eg. TLS). See also +z SECUREONLY.
t TOPIC_LOCK RFC1459 Topic is locked, and can only be changed by channel operators
T NO_NOTICE Charybdis? No NOTICEs can be sent to this channel
u AUDITORIUM Unreal When set, makes /names and /who only show channel operators
u FOUNDER tr-ircd Gives the specified nickname 'founder' status.
u NOQUITPARTS QuakeNet When set, this hides all part messages (no part reasons are broadcast) and all quit reasons are simply replaced with a generic string such as \
v VOICE RFC1459 Nickname Gives the specified nickname a voice. The user may then speak when the channel is being moderated (+m).
V NO_INVITE Unreal Stop channel members inviting people
w AUTO_OP InspIRCd <flag>:<mask> Users that match the given mask will have the given modes when they join the channel.
X EXEMPT_CHANOPS InspIRCd <flag>:<restriction> Lets users who have the given permission flag (or above) bypass certain restrictions
y OPER_PREFIX InspIRCd Marks a user as an oper in the channel with a defined prefix in front of their nick.
Y OJOIN InspIRCd Marks a user as an oper in the channel with a defined prefix in front of their nick, when an IRC oper issues the OJOIN command.
z SECUREONLY Unreal Only allows clients connected via secure connections to join (eg. TLS). See also +S SECURED_ONLY.
z OP_MODERATED Charybdis? Messages blocked by +m, +b, and +q are instead sent to ops
Z NAMED_MODES InspIRCd Allows the display and modification of channel modes with long-form names.
Z ISSECURE Unreal All users currently in the channel are connected through SSL (set and unset as users part and join)