When I type
/list in IRSSI, it says:
Irssi: Doing this is not a good idea. Add -YES option to command if you really mean it
Why is it not a good idea?
On big networks the
LIST command can cause large amounts of data to be dumped to the user (as of writing this post: ~820 kB on DALnet, ~1.7 MB on Freenode). In the old days, when 33 kbps dial-up was considered fast, this could cause the user to be disconnected from IRC, probably due to output buffer overflow ("SendQ exceeded") or simply not replying to
PINGs in time ("Ping timeout").
FWIW, I have never had such problems even when using 256 kbps DSL, so the warning could be considered obsolete.
On big networks, the command gives a huge output. That may not be what you want for several reasons: