/ игнорируют <зарубка>, должен сделать это для одного человека, но существует намного больше опций в случае, если Вы хотите соответствовать большему количеству людей.
10.1 Manual ignoring
Irssi's ignoring options should be enough for everyone :)
/IGNORE [-regexp | -word] [-pattern <pattern>] [-replies] [-except]
[-channels <channel>] <mask> <levels> <^levels>
-regexp: <pattern> is a regular expression
-word: <pattern> must match to full words
-pattern: <pattern> must match to the message's text
-replies: Ignore replies to nick in channels. For example
"/IGNORE -replies *!*@*.fi PUBLIC" ignores everyone
from Finland, but also anyone sending message
"tofinnishnick: blahblah".
-except: *DON'T* ignore
-channels: Ignore only in channels
<mask>: Either a nick mask or list of channels
<levels>: List of levels to ignore
<^levels>: List of levels to NOT ignore
(/ignore -except nick notices = /ignore nick ^notices)
/UNIGNORE <ref#> | <mask>
/IGNORE without any arguments displays list of ignores.
The best match always wins, so you can have:
/IGNORE * CTCPS
/IGNORE -except *!*@host.org CTCPS