%9Description:%9

    These are the message levels that are used throughout Irssi; they describe
    what kind of message is displayed.

    These are the common levels you can use:

        ACTIONS         Actions by a nickname.
        CLIENTCRAP      Irssi's internal messages.
        CLIENTERROR     Irssi's internal error messages.
        CLIENTNOTICE    Irssi's internal notices.
        CRAP            Can be almost anything.
        CTCPS           CTCP messages.
        DCC             DCC protocol related messages.
        DCCMSGS         DCC chat messages.
        INVITES         An invite is received.
        JOINS           A nickname joins a channel.
        KICKS           A nickname gets kicked from a channel.
        MODES           A channel mode is modified.
        MSGS            Private messages.
        NICKS           A nickname changes to another nickname.
        NOTICES         Private notices.
        PARTS           A nickname leaves a channel.
        PUBLIC          Public messages in a channel.
        PUBNOTICES      Public notices in a channel.
        QUITS           A nickname disconnects from IRC.
        SNOTES          Notices sent from a server.
        TOPICS          A channel topic is modified.
        WALLOPS         A wallop is received.

    These are the special levels you can use:

        HILIGHT         The text is highlighted.
        NEVER           Never ignores or logs the message.
        HIDDEN          Hides the message when window HIDELEVEL includes HIDDEN.
        NO_ACT          Doesn't trigger any activity in the statusbar.
        NOHILIGHT       The text is not highlighted.
                        Suppresses hilights when used with /ignore.

    When using levels from Irssi scripts, you need to prepend the level with
    'MSGLEVEL_'; for example 'CRAP' becomes 'MSGLEVEL_CRAP'.