The identify-msg capability causes the server to send an "identification"
prefix in the message parameter of PRIVMSG and NOTICES commands.
The prefix is a single character, + (ASCII plus) if the sender is
"identified" according to services, - (ASCII minus) otherwise.
The definition of 'identified' varies between services software. For example:
- "has the +r usermode set" – if services dynamically set/unset the umode;
- "is identified to an account which owns the current nickname" – if services provide such information in other ways;
- "is identified to any account" – if services don't implement nickname ownership at all.
For this reason, the extension must not be used for security purposes.
Example (demonstrated using the account-notify capability):
:user ACCOUNT *
:user PRIVMSG #atheme :-Hello everyone.
:user ACCOUNT user
:user PRIVMSG #atheme :+Now I'm logged in.
:user NICK loser
:loser PRIVMSG #atheme :-I'm still logged in, but my account does not match.
Historical note: There exist pre-IRCv3 servers and clients that implement the
same extension as CAPAB IDENTIFY-MSG. New servers and clients SHOULD NOT
implement the CAPAB command.
In fact, this extension is entirely superseded by the newer capabilities
account-msg, account-notify, and extended-join, which also allow for
services implementations that have account names different from nicknames. The
identify-msg extension therefore should not be implemented.