irssi/docs/faq.txt

Q: Why doesn't irssi display colors even when ircii etc. displays them?
A: They force ANSI colors even if terminal doesn't support them. By default,
   irssi uses colors only if terminfo/termcap so says. The correct way to
   fix this would be to change your TERM environment to a value where colors
   work, like xterm-color or color_xterm. If this doesn't help, then use the
   evil way of /SET term_force_colors ON.

Q: How do I easily write text to channel that starts with '/' character?
A: / /text

Q: Why doesn't irssi update my realname (or whatever) after I change it
   with /SET realname and reconnect with /RECONNECT or /SERVER?
A: Irssi is trying to be too smart. This will be fixed in future, but for
   now you should use /DISCONNECT + /CONNECT.

Q: I connected to some server which isn't responding but now irssi tries
   to connect back to it all the time! How can I stop it?
A: Two ways. The "good way" to do it is with /DISCONNECT. Check the server
   tags first with /SERVER without giving it any parameters, reconnections
   are those that have tag starting with "recon" text. So most probably you're
   going to do /DISCONNECT recon-1. The other way is to remove all the
   reconnections with /RMRECONNS, easier but may remove some connections
   you actually wanted to reconnect (if you used multiple servers..).

Q: How do I add seconds to timestamp?
A: "/FORMAT timestamp {timestamp %%H:%%M:%%S} " - and remember to add the
   trailing space :)

Q: Why does irssi say "Irssi: Channel not fully synchronized yet, try again
   after a while" when I try to use /BAN etc?
A: Possibly a bug in irssi, or ircd you're using does something that irssi
   didn't really notice. The new code should make this happen far less often
   than before, but one known reason for this is when irssi doesn't notice
   that you were unable to join some channel. Currently however I don't know
   of any such events irssi doesn't know about.

   Anyway, if this does happen, do "/RAWLOG SAVE ~/rawlog" soon after joining
   to channel, and either try to figure out yourself why irssi didn't get
   reply to WHO request, or send the whole log to tss@iki.fi. Note that the
   rawlog is by default only 200 lines and it may not be enough to show all
   needed information, so you might want to do /SET rawlog_lines 1000 or so.

Q: Where's the GUI version?
A: Read http://irssi.org/?page=about

Q: How do I autorejoin channels after being kicked?
A: That's evil and you shouldn't do it. If you get kicked, you should
   stay out, at least until the channel forgot you existed :) Most channels
   I've joined just ban you if you autorejoin after kick. If you're joined
   to channels who kick people for fun, try changing channels or something.

   Anyway, if you REALLY want to do that, and you understand that you're
   doing evilness, you can use the autorejoin.pl script that comes with
   irssi. You'll still need to specify the channels you wish to rejoin with
   /SET autorejoin_channels #chan1 #chan2 ...

Q: How do I announce that I'm away/back in all channels I've joined?
   Or how do I change my nick when setting myself away/back?
A: That's even worse than autorejoin. Who could possibly care every time you
   come and go? Many channels will kick you for using this, and I for example
   have added several ignores so I'd never need to see these messages. Learn
   to use /AWAY command properly and tell it's existence to people who don't
   know about it. /WII yournick shows your away reason much better for people
   who actually want to know if you're there or not.

   You can script these behaviours if you really wish to of course. But
   currently there's no public scripts for either of these, and the only way
   I'm going to add such to irssi.org is if the script contains a setting to
   specify which specific channels the announcement is sent.