Using the IRC Transport

The IRC transport will allow you to access any IRC network through your Jabber client as though they were Jabber chat rooms. To access the client you must join a new chat and use the following address format:

[channel]%[network]@irc.jabber.me.uk

Example

ubuntu%irc.freenode.org@irc.jabber.me.uk (will join the #ubuntu channel on the Freenode network)

Note: The channel name does not include the hash/pound (#) symbol.

The nickname you specify when adding the chat will be used as the IRC /nick.

To send a /msg you must send a message to the user using the following format:

[user]![network]@irc.jabber.me.uk

Example

nickserv!irc.freenode.org@irc.jabber.me.uk (Send a /msg to the nickserv user)

The IRC transport will handle the necessary IRC commands allowing you to identify by simply send the message "identify MyPassword" to the nickserv user now in your roster*.

*nickserv will usually contact you first showing as a "Not in Roster" user

via: https://jmukstatus.wordpress.com/using-the-irc-transport