RFC 1459, IRC : Message details


4. Message details

   On the following pages are descriptions of each message recognized by
   the IRC server and client.  All commands described in this section
   must be implemented by any server for this protocol.

   Where the reply ERR_NOSUCHSERVER is listed, it means that the
   <server> parameter could not be found.  The server must not send any
   other replies after this for that command.

   The server to which a client is connected is required to parse the
   complete message, returning any appropriate errors.  If the server
   encounters a fatal error while parsing a message, an error must be
   sent back to the client and the parsing terminated.  A fatal error
   may be considered to be incorrect command, a destination which is
   otherwise unknown to the server (server, nick or channel names fit
   this category), not enough parameters or incorrect privileges.

   If a full set of parameters is presented, then each must be checked
   for validity and appropriate responses sent back to the client.  In
   the case of messages which use parameter lists using the comma as an
   item separator, a reply must be sent for each item.

   In the examples below, some messages appear using the full format:

   :Name COMMAND parameter list

   Such examples represent a message from "Name" in transit between
   servers, where it is essential to include the name of the original
   sender of the message so remote servers may send back a reply along
   the correct path.

4.1. Connection Registration

   The commands described here are used to register a connection with an
   IRC server as either a user or a server as well as correctly
   disconnect.

   A "PASS" command is not required for either client or server
   connection to be registered, but it must precede the server message
   or the latter of the NICK/USER combination.  It is strongly
   recommended that all server connections have a password in order to
   give some level of security to the actual connections.  The
   recommended order for a client to register is as follows:

           1. Pass message
           2. Nick message
           3. User message

4.1.1. Password message

      Command: PASS
   Parameters: <password>

   The PASS command is used to set a 'connection password'.  The
   password can and must be set before any attempt to register the
   connection is made.  Currently this requires that clients send a PASS
   command before sending the NICK/USER combination and servers *must*
   send a PASS command before any SERVER command.  The password supplied
   must match the one contained in the C/N lines (for servers) or I
   lines (for clients).  It is possible to send multiple PASS commands
   before registering but only the last one sent is used for
   verification and it may not be changed once registered.  Numeric
   Replies:

           ERR_NEEDMOREPARAMS              ERR_ALREADYREGISTRED

   Example:

           PASS secretpasswordhere

4.1.2. Nick message

      Command: NICK
   Parameters: <nickname> [ <hopcount> ]

   NICK message is used to give user a nickname or change the previous
   one.  The <hopcount> parameter is only used by servers to indicate
   how far away a nick is from its home server.  A local connection has
   a hopcount of 0.  If supplied by a client, it must be ignored.

   If a NICK message arrives at a server which already knows about an
   identical nickname for another client, a nickname collision occurs.
   As a result of a nickname collision, all instances of the nickname
   are removed from the server's database, and a KILL command is issued
   to remove the nickname from all other server's database. If the NICK
   message causing the collision was a nickname change, then the
   original (old) nick must be removed as well.

   If the server recieves an identical NICK from a client which is
   directly connected, it may issue an ERR_NICKCOLLISION to the local
   client, drop the NICK command, and not generate any kills.

   Numeric Replies:

           ERR_NONICKNAMEGIVEN             ERR_ERRONEUSNICKNAME
           ERR_NICKNAMEINUSE               ERR_NICKCOLLISION

   Example:

   NICK Wiz                        ; Introducing new nick "Wiz".

   :WiZ NICK Kilroy                ; WiZ changed his nickname to Kilroy.

4.1.3. User message

      Command: USER
   Parameters: <username> <hostname> <servername> <realname>

   The USER message is used at the beginning of connection to specify
   the username, hostname, servername and realname of s new user.  It is
   also used in communication between servers to indicate new user
   arriving on IRC, since only after both USER and NICK have been
   received from a client does a user become registered.

   Between servers USER must to be prefixed with client's NICKname.
   Note that hostname and servername are normally ignored by the IRC
   server when the USER command comes from a directly connected client
   (for security reasons), but they are used in server to server
   communication.  This means that a NICK must always be sent to a
   remote server when a new user is being introduced to the rest of the
   network before the accompanying USER is sent.

   It must be noted that realname parameter must be the last parameter,
   because it may contain space characters and must be prefixed with a
   colon (':') to make sure this is recognised as such.

   Since it is easy for a client to lie about its username by relying
   solely on the USER message, the use of an "Identity Server" is
   recommended.  If the host which a user connects from has such a
   server enabled the username is set to that as in the reply from the
   "Identity Server".

   Numeric Replies:

           ERR_NEEDMOREPARAMS              ERR_ALREADYREGISTRED

   Examples:

   USER guest tolmoon tolsun :Ronnie Reagan

                                   ; User registering themselves with a
                                   username of "guest" and real name
                                   "Ronnie Reagan".

   :testnick USER guest tolmoon tolsun :Ronnie Reagan
                                   ; message between servers with the
                                   nickname for which the USER command
                                   belongs to

4.1.4. Server message

      Command: SERVER
   Parameters: <servername> <hopcount> <info>

   The server message is used to tell a server that the other end of a
   new connection is a server. This message is also used to pass server
   data over whole net.  When a new server is connected to net,
   information about it be broadcast to the whole network.  <hopcount>
   is used to give all servers some internal information on how far away
   all servers are.  With a full server list, it would be possible to
   construct a map of the entire server tree, but hostmasks prevent this
   from being done.

   The SERVER message must only be accepted from either (a) a connection
   which is yet to be registered and is attempting to register as a
   server, or (b) an existing connection to another server, in  which
   case the SERVER message is introducing a new server behind that
   server.

   Most errors that occur with the receipt of a SERVER command result in
   the connection being terminated by the destination host (target
   SERVER).  Error replies are usually sent using the "ERROR" command
   rather than the numeric since the ERROR command has several useful
   properties which make it useful here.

   If a SERVER message is parsed and attempts to introduce a server
   which is already known to the receiving server, the connection from
   which that message must be closed (following the correct procedures),
   since a duplicate route to a server has formed and the acyclic nature
   of the IRC tree broken.

   Numeric Replies:

           ERR_ALREADYREGISTRED

   Example:

SERVER test.oulu.fi 1 :[tolsun.oulu.fi] Experimental server
                                ; New server test.oulu.fi introducing
                                itself and attempting to register.  The
                                name in []'s is the hostname for the
                                host running test.oulu.fi.

:tolsun.oulu.fi SERVER csd.bu.edu 5 :BU Central Server
                                ; Server tolsun.oulu.fi is our uplink
                                for csd.bu.edu which is 5 hops away.

4.1.5. Oper

      Command: OPER
   Parameters: <user> <password>

   OPER message is used by a normal user to obtain operator privileges.
   The combination of <user> and <password> are required to gain
   Operator privileges.

   If the client sending the OPER command supplies the correct password
   for the given user, the server then informs the rest of the network
   of the new operator by issuing a "MODE +o" for the clients nickname.

   The OPER message is client-server only.

   Numeric Replies:

           ERR_NEEDMOREPARAMS              RPL_YOUREOPER
           ERR_NOOPERHOST                  ERR_PASSWDMISMATCH

   Example:

   OPER foo bar                    ; Attempt to register as an operator
                                   using a username of "foo" and "bar" as
                                   the password.

4.1.6. Quit

      Command: QUIT
   Parameters: [<Quit message>]

   A client session is ended with a quit message.  The server must close
   the connection to a client which sends a QUIT message. If a "Quit
   Message" is given, this will be sent instead of the default message,
   the nickname.

   When netsplits (disconnecting of two servers) occur, the quit message

   is composed of the names of two servers involved, separated by a
   space.  The first name is that of the server which is still connected
   and the second name is that of the server that has become
   disconnected.

   If, for some other reason, a client connection is closed without  the
   client  issuing  a  QUIT  command  (e.g.  client  dies and EOF occurs
   on socket), the server is required to fill in the quit  message  with
   some sort  of  message  reflecting the nature of the event which
   caused it to happen.

   Numeric Replies:

           None.

   Examples:

   QUIT :Gone to have lunch        ; Preferred message format.

4.1.7. Server quit message

      Command: SQUIT
   Parameters: <server> <comment>

   The SQUIT message is needed to tell about quitting or dead servers.
   If a server wishes to break the connection to another server it must
   send a SQUIT message to the other server, using the the name of the
   other server as the server parameter, which then closes its
   connection to the quitting server.

   This command is also available operators to help keep a network of
   IRC servers connected in an orderly fashion.  Operators may also
   issue an SQUIT message for a remote server connection.  In this case,
   the SQUIT must be parsed by each server inbetween the operator and
   the remote server, updating the view of the network held by each
   server as explained below.

   The <comment> should be supplied by all operators who execute a SQUIT
   for a remote server (that is not connected to the server they are
   currently on) so that other operators are aware for the reason of
   this action.  The <comment> is also filled in by servers which may
   place an error or similar message here.

   Both of the servers which are on either side of the connection being
   closed are required to to send out a SQUIT message (to all its other
   server connections) for all other servers which are considered to be
   behind that link.

   Similarly, a QUIT message must be sent to the other connected servers
   rest of the network on behalf of all clients behind that link.  In
   addition to this, all channel members of a channel which lost a
   member due to the split must be sent a QUIT message.

   If a server connection is terminated prematurely (e.g. the server  on
   the  other  end  of  the  link  died),  the  server  which  detects
   this disconnection is required to inform the rest of  the  network
   that  the connection  has  closed  and  fill  in  the comment field
   with something appropriate.

   Numeric replies:

           ERR_NOPRIVILEGES                ERR_NOSUCHSERVER

   Example:

   SQUIT tolsun.oulu.fi :Bad Link ? ; the server link tolson.oulu.fi has
                                   been terminated because of "Bad Link".

   :Trillian SQUIT cm22.eng.umd.edu :Server out of control
                                    ; message from Trillian to disconnect
                                   "cm22.eng.umd.edu" from the net
                                    because "Server out of control".

4.2. Channel operations

   This group of messages is concerned with manipulating channels, their
   properties (channel modes), and their contents (typically clients).
   In implementing these, a number of race conditions are inevitable
   when clients at opposing ends of a network send commands which will
   ultimately clash.  It is also required that servers keep a nickname
   history to ensure that wherever a <nick> parameter is given, the
   server check its history in case it has recently been changed.

4.2.1. Join message

      Command: JOIN
   Parameters: <channel>{,<channel>} [<key>{,<key>}]

   The JOIN command is used by client to start listening a specific
   channel. Whether or not a client is allowed to join a channel is
   checked only by the server the client is connected to; all other
   servers automatically add the user to the channel when it is received
   from other servers.  The conditions which affect this are as follows:

           1.  the user must be invited if the channel is invite-only;

           2.  the user's nick/username/hostname must not match any
               active bans;

           3.  the correct key (password) must be given if it is set.

   These are discussed in more detail under the MODE command (see
   section 4.2.3 for more details).

   Once a user has joined a channel, they receive notice about all
   commands their server receives which affect the channel.  This
   includes MODE, KICK, PART, QUIT and of course PRIVMSG/NOTICE.  The
   JOIN command needs to be broadcast to all servers so that each server
   knows where to find the users who are on the channel.  This allows
   optimal delivery of PRIVMSG/NOTICE messages to the channel.

   If a JOIN is successful, the user is then sent the channel's topic
   (using RPL_TOPIC) and the list of users who are on the channel (using
   RPL_NAMREPLY), which must include the user joining.

   Numeric Replies:

           ERR_NEEDMOREPARAMS              ERR_BANNEDFROMCHAN
           ERR_INVITEONLYCHAN              ERR_BADCHANNELKEY
           ERR_CHANNELISFULL               ERR_BADCHANMASK
           ERR_NOSUCHCHANNEL               ERR_TOOMANYCHANNELS
           RPL_TOPIC

   Examples:

   JOIN #foobar                    ; join channel #foobar.

   JOIN &foo fubar                 ; join channel &foo using key "fubar".

   JOIN #foo,&bar fubar            ; join channel #foo using key "fubar"
                                   and &bar using no key.

   JOIN #foo,#bar fubar,foobar     ; join channel #foo using key "fubar".
                                   and channel #bar using key "foobar".

   JOIN #foo,#bar                  ; join channels #foo and #bar.

   :WiZ JOIN #Twilight_zone        ; JOIN message from WiZ

4.2.2. Part message

      Command: PART
   Parameters: <channel>{,<channel>}

   The PART message causes the client sending the message to be removed
   from the list of active users for all given channels listed in the
   parameter string.

   Numeric Replies:

           ERR_NEEDMOREPARAMS              ERR_NOSUCHCHANNEL
           ERR_NOTONCHANNEL

   Examples:

   PART #twilight_zone             ; leave channel "#twilight_zone"

   PART #oz-ops,&group5            ; leave both channels "&group5" and
                                   "#oz-ops".

4.2.3. Mode message

      Command: MODE

   The MODE command is a dual-purpose command in IRC.  It allows both
   usernames and channels to have their mode changed.  The rationale for
   this choice is that one day nicknames will be obsolete and the
   equivalent property will be the channel.

   When parsing MODE messages, it is recommended that the entire message
   be parsed first and then the changes which resulted then passed on.

4.2.3.1. Channel modes

   Parameters: <channel> {[+|-]|o|p|s|i|t|n|b|v} [<limit>] [<user>]
               [<ban mask>]

   The MODE command is provided so that channel operators may change the
   characteristics of `their' channel.  It is also required that servers
   be able to change channel modes so that channel operators may be
   created.

   The various modes available for channels are as follows:

           o - give/take channel operator privileges;
           p - private channel flag;
           s - secret channel flag;
           i - invite-only channel flag;
           t - topic settable by channel operator only flag;
           n - no messages to channel from clients on the outside;
           m - moderated channel;
           l - set the user limit to channel;

           b - set a ban mask to keep users out;
           v - give/take the ability to speak on a moderated channel;
           k - set a channel key (password).

   When using the 'o' and 'b' options, a restriction on a total of three
   per mode command has been imposed.  That is, any combination of 'o'
   and

4.2.3.2. User modes

   Parameters: <nickname> {[+|-]|i|w|s|o}

   The user MODEs are typically changes which affect either how the
   client is seen by others or what 'extra' messages the client is sent.
   A user MODE command may only be accepted if both the sender of the
   message and the nickname given as a parameter are both the same.

   The available modes are as follows:

           i - marks a users as invisible;
           s - marks a user for receipt of server notices;
           w - user receives wallops;
           o - operator flag.

   Additional modes may be available later on.

   If a user attempts to make themselves an operator using the "+o"
   flag, the attempt should be ignored.  There is no restriction,
   however, on anyone `deopping' themselves (using "-o").  Numeric
   Replies:

           ERR_NEEDMOREPARAMS              RPL_CHANNELMODEIS
           ERR_CHANOPRIVSNEEDED            ERR_NOSUCHNICK
           ERR_NOTONCHANNEL                ERR_KEYSET
           RPL_BANLIST                     RPL_ENDOFBANLIST
           ERR_UNKNOWNMODE                 ERR_NOSUCHCHANNEL

           ERR_USERSDONTMATCH              RPL_UMODEIS
           ERR_UMODEUNKNOWNFLAG

   Examples:

           Use of Channel Modes:

MODE #Finnish +im               ; Makes #Finnish channel moderated and
                                'invite-only'.

MODE #Finnish +o Kilroy         ; Gives 'chanop' privileges to Kilroy on

                                channel #Finnish.

MODE #Finnish +v Wiz            ; Allow WiZ to speak on #Finnish.

MODE #Fins -s                   ; Removes 'secret' flag from channel
                                #Fins.

MODE #42 +k oulu                ; Set the channel key to "oulu".

MODE #eu-opers +l 10            ; Set the limit for the number of users
                                on channel to 10.

MODE &oulu +b                   ; list ban masks set for channel.

MODE &oulu +b *!*@*             ; prevent all users from joining.

MODE &oulu +b *!*@*.edu         ; prevent any user from a hostname
                                matching *.edu from joining.

        Use of user Modes:

:MODE WiZ -w                    ; turns reception of WALLOPS messages
                                off for WiZ.

:Angel MODE Angel +i            ; Message from Angel to make themselves
                                invisible.

MODE WiZ -o                     ; WiZ 'deopping' (removing operator
                                status).  The plain reverse of this
                                command ("MODE WiZ +o") must not be
                                allowed from users since would bypass
                                the OPER command.

4.2.4. Topic message

      Command: TOPIC
   Parameters: <channel> [<topic>]

   The TOPIC message is used to change or view the topic of a channel.
   The topic for channel <channel> is returned if there is no <topic>
   given.  If the <topic> parameter is present, the topic for that
   channel will be changed, if the channel modes permit this action.

   Numeric Replies:

           ERR_NEEDMOREPARAMS              ERR_NOTONCHANNEL
           RPL_NOTOPIC                     RPL_TOPIC
           ERR_CHANOPRIVSNEEDED

   Examples:

   :Wiz TOPIC #test :New topic     ;User Wiz setting the topic.

   TOPIC #test :another topic      ;set the topic on #test to "another
                                   topic".

   TOPIC #test                     ; check the topic for #test.

4.2.5. Names message

      Command: NAMES
   Parameters: [<channel>{,<channel>}]

   By using the NAMES command, a user can list all nicknames that are
   visible to them on any channel that they can see.  Channel names
   which they can see are those which aren't private (+p) or secret (+s)
   or those which they are actually on.  The <channel> parameter
   specifies which channel(s) to return information about if valid.
   There is no error reply for bad channel names.

   If no <channel> parameter is given, a list of all channels and their
   occupants is returned.  At the end of this list, a list of users who
   are visible but either not on any channel or not on a visible channel
   are listed as being on `channel' "*".

   Numerics:

           RPL_NAMREPLY                    RPL_ENDOFNAMES

   Examples:

   NAMES #twilight_zone,#42        ; list visible users on #twilight_zone
                                   and #42 if the channels are visible to
                                   you.

   NAMES                           ; list all visible channels and users

4.2.6. List message

      Command: LIST
   Parameters: [<channel>{,<channel>} [<server>]]

   The list message is used to list channels and their topics.  If  the
   <channel>  parameter  is  used,  only  the  status  of  that  channel
   is displayed.  Private  channels  are  listed  (without  their
   topics)  as channel "Prv" unless the client generating the query is
   actually on that channel.  Likewise, secret channels are not listed

   at  all  unless  the client is a member of the channel in question.

   Numeric Replies:

           ERR_NOSUCHSERVER                RPL_LISTSTART
           RPL_LIST                        RPL_LISTEND

   Examples:

   LIST                            ; List all channels.

   LIST #twilight_zone,#42         ; List channels #twilight_zone and #42

4.2.7. Invite message

      Command: INVITE
   Parameters: <nickname> <channel>

   The INVITE message is used to invite users to a channel.  The
   parameter <nickname> is the nickname of the person to be invited to
   the target channel <channel>.  There is no requirement that the
   channel the target user is being invited to must exist or be a valid
   channel.  To invite a user to a channel which is invite only (MODE
   +i), the client sending the invite must be recognised as being a
   channel operator on the given channel.

   Numeric Replies:

           ERR_NEEDMOREPARAMS              ERR_NOSUCHNICK
           ERR_NOTONCHANNEL                ERR_USERONCHANNEL
           ERR_CHANOPRIVSNEEDED
           RPL_INVITING                    RPL_AWAY

   Examples:

   :Angel INVITE Wiz #Dust         ; User Angel inviting WiZ to channel
                                   #Dust

   INVITE Wiz #Twilight_Zone       ; Command to invite WiZ to
                                   #Twilight_zone

4.2.8. Kick command

      Command: KICK
   Parameters: <channel> <user> [<comment>]

   The KICK command can be  used  to  forcibly  remove  a  user  from  a
   channel.   It  'kicks  them  out'  of the channel (forced PART).

   Only a channel operator may kick another user out of a  channel.
   Each  server that  receives  a KICK message checks that it is valid
   (ie the sender is actually a  channel  operator)  before  removing
   the  victim  from  the channel.

   Numeric Replies:

           ERR_NEEDMOREPARAMS              ERR_NOSUCHCHANNEL
           ERR_BADCHANMASK                 ERR_CHANOPRIVSNEEDED
           ERR_NOTONCHANNEL

   Examples:

KICK &Melbourne Matthew         ; Kick Matthew from &Melbourne

KICK #Finnish John :Speaking English
                                ; Kick John from #Finnish using
                                "Speaking English" as the reason
                                (comment).

:WiZ KICK #Finnish John         ; KICK message from WiZ to remove John
                                from channel #Finnish

NOTE:
     It is possible to extend the KICK command parameters to the
following:

<channel>{,<channel>} <user>{,<user>} [<comment>]

4.3. Server queries and commands

   The server query group of commands has been designed to return
   information about any server which is connected to the network.  All
   servers connected must respond to these queries and respond
   correctly.  Any invalid response (or lack thereof) must be considered
   a sign of a broken server and it must be disconnected/disabled as
   soon as possible until the situation is remedied.

   In these queries, where a parameter appears as "<server>", it will
   usually mean it can be a nickname or a server or a wildcard name of
   some sort.  For each parameter, however, only one query and set of
   replies is to be generated.

4.3.1. Version message

      Command: VERSION
   Parameters: [<server>]

   The VERSION message is used  to  query  the  version  of  the  server
   program.  An optional parameter <server> is used to query the version
   of the server program which a client is not directly connected to.

   Numeric Replies:

           ERR_NOSUCHSERVER                RPL_VERSION

   Examples:

   :Wiz VERSION *.se               ; message from Wiz to check the version
                                   of a server matching "*.se"

   VERSION tolsun.oulu.fi          ; check the version of server
                                   "tolsun.oulu.fi".

4.3.2. Stats message

      Command: STATS
   Parameters: [<query> [<server>]]

   The stats message is used to query statistics of certain server.  If
   <server> parameter is omitted, only the end of stats reply is sent
   back.  The implementation of this command is highly dependent on the
   server which replies, although the server must be able to supply
   information as described by the queries below (or similar).

   A query may be given by any single letter which is only checked by
   the destination server (if given as the <server> parameter) and is
   otherwise passed on by intermediate servers, ignored and unaltered.
   The following queries are those found in the current IRC
   implementation and provide a large portion of the setup information
   for that server.  Although these may not be supported in the same way
   by other versions, all servers should be able to supply a valid reply
   to a STATS query which is consistent with the reply formats currently
   used and the purpose of the query.

   The currently supported queries are:

           c - returns a list of servers which the server may connect
               to or allow connections from;
           h - returns a list of servers which are either forced to be
               treated as leaves or allowed to act as hubs;
           i - returns a list of hosts which the server allows a client
               to connect from;
           k - returns a list of banned username/hostname combinations
               for that server;
           l - returns a list of the server's connections, showing how

               long each connection has been established and the traffic
               over that connection in bytes and messages for each
               direction;
           m - returns a list of commands supported by the server and
               the usage count for each if the usage count is non zero;
           o - returns a list of hosts from which normal clients may
               become operators;
           y - show Y (Class) lines from server's configuration file;
           u - returns a string showing how long the server has been up.

   Numeric Replies:

           ERR_NOSUCHSERVER
           RPL_STATSCLINE                  RPL_STATSNLINE
           RPL_STATSILINE                  RPL_STATSKLINE
           RPL_STATSQLINE                  RPL_STATSLLINE
           RPL_STATSLINKINFO               RPL_STATSUPTIME
           RPL_STATSCOMMANDS               RPL_STATSOLINE
           RPL_STATSHLINE                  RPL_ENDOFSTATS

   Examples:

STATS m                         ; check the command usage for the server
                                you are connected to

:Wiz STATS c eff.org            ; request by WiZ for C/N line
                                information from server eff.org

4.3.3. Links message

      Command: LINKS
   Parameters: [[<remote server>] <server mask>]

   With LINKS, a user can list all servers which are known by the server
   answering the query.  The returned list of servers must match the
   mask, or if no mask is given, the full list is returned.

   If <remote server> is given in addition to <server mask>, the LINKS
   command is forwarded to the first server found that matches that name
   (if any), and that server is then required to answer the query.

   Numeric Replies:

           ERR_NOSUCHSERVER
           RPL_LINKS                       RPL_ENDOFLINKS

   Examples:

LINKS *.au                      ; list all servers which have a name
                                that matches *.au;

:WiZ LINKS *.bu.edu *.edu       ; LINKS message from WiZ to the first
                                server matching *.edu for a list of
                                servers matching *.bu.edu.

4.3.4. Time message

      Command: TIME
   Parameters: [<server>]

   The time message is used to query local time from the specified
   server. If the server parameter is not given, the server handling the
   command must reply to the query.

   Numeric Replies:

           ERR_NOSUCHSERVER                RPL_TIME

   Examples:

   TIME tolsun.oulu.fi             ; check the time on the server
                                   "tolson.oulu.fi"

   Angel TIME *.au                 ; user angel checking the time on a
                                   server matching "*.au"

4.3.5. Connect message

      Command: CONNECT
   Parameters: <target server> [<port> [<remote server>]]

   The CONNECT command can be used to force a server to try to establish
   a new connection to another server immediately.  CONNECT is a
   privileged command and is to be available only to IRC Operators.  If
   a remote server is given then the CONNECT attempt is made by that
   server to <target server> and <port>.

   Numeric Replies:

           ERR_NOSUCHSERVER                ERR_NOPRIVILEGES
           ERR_NEEDMOREPARAMS

   Examples:

CONNECT tolsun.oulu.fi          ; Attempt to connect a server to
                                tolsun.oulu.fi

:WiZ CONNECT eff.org 6667 csd.bu.edu
                                ; CONNECT attempt by WiZ to get servers
                                eff.org and csd.bu.edu connected on port
                                6667.

4.3.6. Trace message

      Command: TRACE
   Parameters: [<server>]

   TRACE command is used to find the route to specific server.  Each
   server that processes this message must tell the sender about it by
   sending a reply indicating it is a pass-through link, forming a chain
   of replies similar to that gained from using "traceroute".  After
   sending this reply back, it must then send the TRACE message to the
   next server until given server is reached.  If the <server> parameter
   is omitted, it is recommended that TRACE command send a message to
   the sender telling which servers the current server has direct
   connection to.

   If the destination given by "<server>" is an actual server, then the
   destination server is required to report all servers and users which
   are connected to it, although only operators are permitted to see
   users present.  If the destination given by <server> is a nickname,
   they only a reply for that nickname is given.

   Numeric Replies:

           ERR_NOSUCHSERVER

   If the TRACE message is destined for another server, all intermediate
   servers must return a RPL_TRACELINK reply to indicate that the TRACE
   passed through it and where its going next.

           RPL_TRACELINK
   A TRACE reply may be composed of any number of the following numeric
   replies.

           RPL_TRACECONNECTING             RPL_TRACEHANDSHAKE
           RPL_TRACEUNKNOWN                RPL_TRACEOPERATOR
           RPL_TRACEUSER                   RPL_TRACESERVER
           RPL_TRACESERVICE                RPL_TRACENEWTYPE
           RPL_TRACECLASS

   Examples:

TRACE *.oulu.fi                 ; TRACE to a server matching *.oulu.fi

:WiZ TRACE AngelDust            ; TRACE issued by WiZ to nick AngelDust

4.3.7. Admin command

      Command: ADMIN
   Parameters: [<server>]

   The admin message is used to find the name of the administrator of
   the given server, or current server if <server> parameter is omitted.
   Each server must have the ability to forward ADMIN messages to other
   servers.

   Numeric Replies:

           ERR_NOSUCHSERVER
           RPL_ADMINME                     RPL_ADMINLOC1
           RPL_ADMINLOC2                   RPL_ADMINEMAIL

   Examples:

   ADMIN tolsun.oulu.fi            ; request an ADMIN reply from
                                   tolsun.oulu.fi

   :WiZ ADMIN *.edu                ; ADMIN request from WiZ for first
                                   server found to match *.edu.

4.3.8. Info command

      Command: INFO
   Parameters: [<server>]

   The INFO command is required to return information which describes
   the server: its version, when it was compiled, the patchlevel, when
   it was started, and any other miscellaneous information which may be
   considered to be relevant.

   Numeric Replies:

           ERR_NOSUCHSERVER
           RPL_INFO                        RPL_ENDOFINFO

   Examples:

   INFO csd.bu.edu                 ; request an INFO reply from
   csd.bu.edu

   :Avalon INFO *.fi               ; INFO request from Avalon for first
                                   server found to match *.fi.

   INFO Angel                      ; request info from the server that
                                   Angel is connected to.

4.4. Sending messages

   The main purpose of the IRC protocol is to provide a base for clients
   to communicate with each other.  PRIVMSG and NOTICE are the only
   messages available which actually perform delivery of a text message
   from one client to another - the rest just make it possible and try
   to ensure it happens in a reliable and structured manner.

4.4.1. Private messages

      Command: PRIVMSG
   Parameters: <receiver>{,<receiver>} <text to be sent>

   PRIVMSG is used to send private messages between users.  <receiver>
   is the nickname of the receiver of the message.  <receiver> can also
   be a list of names or channels separated with commas.

   The <receiver> parameter may also me a host mask  (#mask)  or  server
   mask  ($mask).   In  both cases the server will only send the PRIVMSG
   to those who have a server or host matching the mask.  The mask  must
   have at  least  1  (one)  "."  in it and no wildcards following the
   last ".".  This requirement exists to prevent people sending messages
   to  "#*"  or "$*",  which  would  broadcast  to  all  users; from
   experience, this is abused more than used responsibly and properly.
   Wildcards are  the  '*' and  '?'   characters.   This  extension  to
   the PRIVMSG command is only available to Operators.

   Numeric Replies:

           ERR_NORECIPIENT                 ERR_NOTEXTTOSEND
           ERR_CANNOTSENDTOCHAN            ERR_NOTOPLEVEL
           ERR_WILDTOPLEVEL                ERR_TOOMANYTARGETS
           ERR_NOSUCHNICK
           RPL_AWAY

   Examples:

:Angel PRIVMSG Wiz :Hello are you receiving this message ?
                                ; Message from Angel to Wiz.

PRIVMSG Angel :yes I'm receiving it !receiving it !'u>(768u+1n) .br ;
                                Message to Angel.

PRIVMSG jto@tolsun.oulu.fi :Hello !
                                ; Message to a client on server

                                tolsun.oulu.fi with username of "jto".

PRIVMSG $*.fi :Server tolsun.oulu.fi rebooting.
                                ; Message to everyone on a server which
                                has a name matching *.fi.

PRIVMSG #*.edu :NSFNet is undergoing work, expect interruptions
                                ; Message to all users who come from a
                                host which has a name matching *.edu.

4.4.2. Notice

      Command: NOTICE
   Parameters: <nickname> <text>

   The NOTICE message is used similarly to PRIVMSG.  The difference
   between NOTICE and PRIVMSG is that automatic replies must never be
   sent in response to a NOTICE message.  This rule applies to servers
   too - they must not send any error reply back to the client on
   receipt of a notice.  The object of this rule is to avoid loops
   between a client automatically sending something in response to
   something it received.  This is typically used by automatons (clients
   with either an AI or other interactive program controlling their
   actions) which are always seen to be replying lest they end up in a
   loop with another automaton.

   See PRIVMSG for more details on replies and examples.

4.5. User based queries

   User queries are a group of commands which are primarily concerned
   with finding details on a particular user or group users.  When using
   wildcards with any of these commands, if they match, they will only
   return information on users who are 'visible' to you.  The visibility
   of a user is determined as a combination of the user's mode and the
   common set of channels you are both on.

4.5.1. Who query

      Command: WHO
   Parameters: [<name> [<o>]]

   The WHO message is used by a client to generate a query which returns
   a list of information which 'matches' the <name> parameter given by
   the client.  In the absence of the <name> parameter, all visible
   (users who aren't invisible (user mode +i) and who don't have a
   common channel with the requesting client) are listed.  The same
   result can be achieved by using a <name> of "0" or any wildcard which

   will end up matching every entry possible.

   The <name> passed to WHO is matched against users' host, server, real
   name and nickname if the channel <name> cannot be found.

   If the "o" parameter is passed only operators are returned according
   to the name mask supplied.

   Numeric Replies:

           ERR_NOSUCHSERVER
           RPL_WHOREPLY                    RPL_ENDOFWHO

   Examples:

   WHO *.fi                        ; List all users who match against
                                   "*.fi".

   WHO jto* o                      ; List all users with a match against
                                   "jto*" if they are an operator.

4.5.2. Whois query

      Command: WHOIS
   Parameters: [<server>] <nickmask>[,<nickmask>[,...]]

   This message is used to query information about particular user.  The
   server will answer this message with several numeric messages
   indicating different statuses of each user which matches the nickmask
   (if you are entitled to see them).  If no wildcard is present in the
   <nickmask>, any information about that nick which you are allowed to
   see is presented.  A comma (',') separated list of nicknames may be
   given.

   The latter version sends the query to a specific server.  It is
   useful if you want to know how long the user in question has been
   idle as only local server (ie. the server the user is directly
   connected to) knows that information, while everything else is
   globally known.

   Numeric Replies:

           ERR_NOSUCHSERVER                ERR_NONICKNAMEGIVEN
           RPL_WHOISUSER                   RPL_WHOISCHANNELS
           RPL_WHOISCHANNELS               RPL_WHOISSERVER
           RPL_AWAY                        RPL_WHOISOPERATOR
           RPL_WHOISIDLE                   ERR_NOSUCHNICK
           RPL_ENDOFWHOIS

   Examples:

   WHOIS wiz                       ; return available user information
                                   about nick WiZ

   WHOIS eff.org trillian          ; ask server eff.org for user
                                   information about trillian

4.5.3. Whowas

      Command: WHOWAS
   Parameters: <nickname> [<count> [<server>]]

   Whowas asks for information about a nickname which no longer exists.
   This may either be due to a nickname change or the user leaving IRC.
   In response to this query, the server searches through its nickname
   history, looking for any nicks which are lexically the same (no wild
   card matching here).  The history is searched backward, returning the
   most recent entry first.  If there are multiple entries, up to
   <count> replies will be returned (or all of them if no <count>
   parameter is given).  If a non-positive number is passed as being
   <count>, then a full search is done.

   Numeric Replies:

           ERR_NONICKNAMEGIVEN             ERR_WASNOSUCHNICK
           RPL_WHOWASUSER                  RPL_WHOISSERVER
           RPL_ENDOFWHOWAS

   Examples:

   WHOWAS Wiz                      ; return all information in the nick
                                   history about nick "WiZ";

   WHOWAS Mermaid 9                ; return at most, the 9 most recent
                                   entries in the nick history for
                                   "Mermaid";

   WHOWAS Trillian 1 *.edu         ; return the most recent history for
                                   "Trillian" from the first server found
                                   to match "*.edu".

4.6. Miscellaneous messages

   Messages in this category do not fit into any of the above categories
   but are nonetheless still a part of and required by the protocol.

4.6.1. Kill message

      Command: KILL
   Parameters: <nickname> <comment>

   The KILL message is used to cause a client-server connection to be
   closed by the server which has the actual connection.  KILL is used
   by servers when they encounter a duplicate entry in the list of valid
   nicknames and is used to remove both entries.  It is also available
   to operators.

   Clients which have automatic reconnect algorithms effectively make
   this command useless since the disconnection is only brief.  It does
   however break the flow of data and can be used to stop large amounts
   of being abused, any user may elect to receive KILL messages
   generated for others to keep an 'eye' on would be trouble spots.

   In an arena where nicknames are required to be globally unique at all
   times, KILL messages are sent whenever 'duplicates' are detected
   (that is an attempt to register two users with the same nickname) in
   the hope that both of them will disappear and only 1 reappear.

   The comment given must reflect the actual reason for the KILL.  For
   server-generated KILLs it usually is made up of details concerning
   the origins of the two conflicting nicknames.  For users it is left
   up to them to provide an adequate reason to satisfy others who see
   it.  To prevent/discourage fake KILLs from being generated to hide
   the identify of the KILLer, the comment also shows a 'kill-path'
   which is updated by each server it passes through, each prepending
   its name to the path.

   Numeric Replies:

           ERR_NOPRIVILEGES                ERR_NEEDMOREPARAMS
           ERR_NOSUCHNICK                  ERR_CANTKILLSERVER

   KILL David (csd.bu.edu <- tolsun.oulu.fi)
                                   ; Nickname collision between csd.bu.edu
                                   and tolson.oulu.fi

   NOTE:
   It is recommended that only Operators be allowed to kill other users
   with KILL message.  In an ideal world not even operators would need
   to do this and it would be left to servers to deal with.

4.6.2. Ping message

      Command: PING
   Parameters: <server1> [<server2>]

   The PING message is used to test the presence of an active client at
   the other end of the connection.  A PING message is sent at regular
   intervals if no other activity detected coming from a connection.  If
   a connection fails to respond to a PING command within a set amount
   of time, that connection is closed.

   Any client which receives a PING message must respond to <server1>
   (server which sent the PING message out) as quickly as possible with
   an appropriate PONG message to indicate it is still there and alive.
   Servers should not respond to PING commands but rely on PINGs from
   the other end of the connection to indicate the connection is alive.
   If the <server2> parameter is specified, the PING message gets
   forwarded there.

   Numeric Replies:

           ERR_NOORIGIN                    ERR_NOSUCHSERVER

   Examples:

   PING tolsun.oulu.fi             ; server sending a PING message to
                                   another server to indicate it is still
                                   alive.

   PING WiZ                        ; PING message being sent to nick WiZ

4.6.3. Pong message

      Command: PONG
   Parameters: <daemon> [<daemon2>]

   PONG message is a reply to ping message.  If parameter <daemon2> is
   given this message must be forwarded to given daemon.  The <daemon>
   parameter is the name of the daemon who has responded to PING message
   and generated this message.

   Numeric Replies:

           ERR_NOORIGIN                    ERR_NOSUCHSERVER

   Examples:

   PONG csd.bu.edu tolsun.oulu.fi  ; PONG message from csd.bu.edu to

                                   tolsun.oulu.fi

4.6.4. Error

      Command: ERROR
   Parameters: <error message>

   The ERROR command is for use by servers when reporting a serious or
   fatal error to its operators.  It may also be sent from one server to
   another but must not be accepted from any normal unknown clients.

   An ERROR message is for use for reporting errors which occur with a
   server-to-server link only.  An ERROR message is sent to the server
   at the other end (which sends it to all of its connected operators)
   and to all operators currently connected.  It is not to be passed
   onto any other servers by a server if it is received from a server.

   When a server sends a received ERROR message to its operators, the
   message should be encapsulated inside a NOTICE message, indicating
   that the client was not responsible for the error.

   Numerics:

           None.

   Examples:

   ERROR :Server *.fi already exists; ERROR message to the other server
                                   which caused this error.

   NOTICE WiZ :ERROR from csd.bu.edu -- Server *.fi already exists
                                   ; Same ERROR message as above but sent
                                   to user WiZ on the other server.