IGNORE %|[-regexp | -full] [-pattern <pattern>] [-except] [-replies] [-network <network>] [-channels <channel>] [-time <secs>] <mask> [<levels>]
IGNORE %|[-regexp | -full] [-pattern <pattern>] [-except] [-replies] [-network <network>] [-time <secs>] <channels> [<levels>]

    -regexp: <pattern> is a regular expression
    -full: <pattern> must match to full words
    -pattern: <pattern> must match to the message's text
    -except: *DON'T* ignore - overrides an existing ignore.
    -replies: Ignore replies to nick in channels. For example
              "/IGNORE -replies *!*@*.fi PUBLIC" ignores everyone
              from Finland, but also anyone sending message
              "tofinnishnick: blahblah".
    -network: Ignore only on this network.
    -ircnet: Same as -network. Deprecated. Do not use.
    -channels: Ignore only in channels
    -time: <secs> seconds after the ignore is removed
    <mask>: Either a nick mask or list of channels
    <levels>: List of levels to ignore. You can use -<level> to remove levels
              from ignore.
    <^levels>: List of levels to NOT ignore
               (/ignore -except nick notices = /ignore nick ^notices)


/IGNORE without any arguments displays list of ignores. If you want to remove some levels of the ignore, use /IGNORE <mask> -<level> -<level2> etc

The best match always wins, so you can have:
    /IGNORE * CTCPS
    /IGNORE -except *!*@host.org CTCPS

Examples:

    /IGNORE * JOINS                         - ignore joins in all channels
    /IGNORE #channel ALL -PUBLIC -ACTIONS   - ignore all but public/actions
    /IGNORE #channel -JOINS                 - don't ignore joins anymore
    /IGNORE -replies *!user@*.host.org ALL  - ignore user and all replies

Some suggestions for ignoring annoying public aways:
    /IGNORE -regexp -pattern "is (away|gone|back)" * ACTIONS
    /IGNORE *zzz* NICKS
    /IGNORE *afk* NICKS
    /IGNORE *away* NICKS

For regular expressions, see `man 7 regex`.

See also: UNIGNORE, SILENCE, ACCEPT