Editing IRC (section)

===Modes===
Users and channels may have ''modes'' that are represented by individual case-sensitive letters<ref>{{cite IETF
| rfc         = 2811
|title=Internet Relay Chat: Channel Management
| sectionname = Channel Modes
| section     = 4
| page        = 7
| idanchor    = ietf
}}</ref> and are set using the ''MODE'' command.<ref>{{cite IETF
| rfc         = 1459
|title=Internet Relay Chat Protocol
| sectionname = Mode message
| section     = 4.2.3
| page        = 21
| idanchor    = ietf
}}</ref> User modes and channel modes are separate and can use the same letter to mean different things (e.g. user mode "i" is invisible mode while channel mode "i" is invite only.<ref>{{cite IETF
| rfc         = 1459
|title=Internet Relay Chat Protocol
| sectionname = Channel modes
| section     = 4.2.3.1
| pages       = 21 – 22
| idanchor    = ietf
}}</ref>) Modes are usually set and unset using the mode command that takes a target (user or channel), a set of modes to set (+) or unset (-) and any parameters the modes need.

Some channel modes take parameters and other channel modes apply to a user on a channel or add or remove a mask (e.g. a ban mask) from a list associated with the channel rather than applying to the channel as a whole.<ref>{{cite IETF
| rfc         = 2811
|title=Internet Relay Chat: Channel Management
| sectionname = Channel Access Control
| section     = 4.3
| pages       = 10 – 11
| idanchor    = ietf
}}</ref> Modes that apply to users on a channel have an associated symbol that is used to represent the mode in names replies<ref name="rfc 1459 p.51 rpl_namreply">{{cite IETF
| rfc         = 1459
|title=Internet Relay Chat Protocol
| sectionname = Command responses: 353 RPL_NAMREPLY
| page        = 51
| idanchor    = ietf
}}</ref> (sent to clients on first joining a channel<ref name="rfc 1459 4.2.1 join message" /> and use of the names command) and in many clients also used to represent it in the client's displayed list of users in a channel or to display an own indicator for a user's modes.

In order to correctly parse incoming mode messages and track channel state the client must know which mode is of which type and for the modes that apply to a user on a channel which symbol goes with which letter. In early implementations of IRC this had to be hard-coded in the client but there is now a de facto standard extension to the protocol called ISUPPORT that sends this information to the client at connect time using numeric 005.<ref>{{cite web
| url         = http://www.irc.org/tech_docs/005.html
| title       = The 005 numeric: ISUPPORT
| access-date  = 10 April 2011
| last        = Roeckx
| first       = Kurt
| date        = 14 October 2004
| publisher   = irc.org
}}</ref><ref>{{cite IETF
| title       = IRC RPL_ISUPPORT Numeric Definition
| draft       = draft-brocklesby-irc-isupport-03
| last        = Brocklesby
| first       = Edward
|date=September 2002
| publisher   = [[Internet Engineering Task Force|IETF]]
| access-date  = 10 April 2011
}}</ref>

There is a small design fault in IRC regarding modes that apply to users on channels: the names message used to establish initial channel state can only send one such mode per user on the channel,<ref name="rfc 1459 p.51 rpl_namreply" /> but multiple such modes can be set on a single user. For example, if a user holds both operator status (+o) and voice status (+v) on a channel, a new client will be unable to see the mode with less priority (i.e. voice). Workarounds for this are possible on both the client and server side; a common solution is to use IRCv3 "multi-prefix" extension.<ref>{{cite web |url=https://ircv3.net/specs/extensions/multi-prefix |title='multi-prefix' Extension - IRCv3}}</ref>

====Standard (RFC 1459) modes====

{| class="wikitable"
|+ User modes
|-
! Letter
! Symbol
! Description
|-
| '''i'''
|
| Invisible—cannot be seen without a common channel or knowing the exact name
|-
| '''s'''
|
| Receives server notices
|-
| '''w'''
|
| Receives wallops<ref>{{cite IETF
| rfc         = 1459
|title=Internet Relay Chat Protocol
| sectionname = Operwall message
| section     = 5.6
| page        = 41
| idanchor    = ietf
}}</ref>
|-
| '''o'''
|
| User is an IRC operator (ircop)
|}

{| class="wikitable"
|+ Channel modes
|-
! Letter
! Symbol
! Parameter(s)
! Description
|-
| '''o'''
| @
| Name of affected user
| Channel operator—can change channel modes and kick users out of the channel among other things
|-
| '''s'''
|
|
| Secret channel—not shown in channel list or user whois except to users already on the channel
|-
| '''p'''
|
|
| Private channel—listed in channel list as "prv" according to <nowiki>RFC 1459</nowiki>
|-
| '''n'''
|
|
| Users cannot send messages to the channel externally
|-
| '''m'''
|
|
| Channel is moderated (only those who hold channel operator or voice status on the channel can send messages to it)
|-
| '''i'''
|
|
| Only users with invites may enter the channel.
|-
| '''t'''
|
|
| Only channel operators can change the channel topic.
|-
| '''l'''
|
| Limit number
| Limits number of users able to be on channel (when full, no new users can join)
|-
| '''b'''
|
| Ban mask (nick!user@host with wildcards allowed)
| Bans [[hostmask]]s from channel
|-
| '''v''' <!-- That does belong here with the channel modes. It's not a user mode -->
| +
| Name of affected user
| Gives a user voice status on channel (see +m above)
|-
| '''k'''
|
| New channel key
| Sets a channel key such that only users knowing the key can enter
|}

Many daemons and networks have added extra modes or modified the behavior of modes in the above list.<ref>{{cite web
| url         = http://www.alien.net.au/irc/usermodes.html
| title       = IRC User Modes List
| access-date  = 10 April 2011
| last        = Butcher
| first       = Simon
| date        = 12 January 2005
| publisher   = alien.net.au
}}</ref><ref>{{cite web
| url         = http://www.alien.net.au/irc/chanmodes.html
| title       = IRC Channel Modes List
| access-date  = 10 April 2011
| last        = Butcher
| first       = Simon
| date        = 12 January 2005
| publisher   = alien.net.au
}}</ref><ref>{{cite web
| url         = http://www.alien.net.au/irc/servermodes.html
| title       = IRC Server Modes List
| access-date  = 10 April 2011
| last        = Butcher
| first       = Simon
| date        = 12 January 2005
| publisher   = alien.net.au
}}</ref><ref>{{cite web
 |url          = http://webtoman.com/opera/panel/ircdmodes.html
 |title        = IRCd Modes
 |access-date   = 10 April 2011
|last         = Olsen
 |first        = Tommy
 |publisher    = webtoman.com
 |archive-url  = https://web.archive.org/web/20111015190740/http://webtoman.com/opera/panel/ircdmodes.html
 |archive-date = 15 October 2011
|url-status   = dead
}}</ref>