@SYNTAX:hilight@

   -mask: Match only for nick, <text> is a nick mask
   -regexp: <text> is a regular expression
   -full: <text> must match to full words
   -nick: Hilight only the nick, not the whole line (default)
   -word: Hilight only the word (default with non-public messages)
   -line: Hilight the whole line with the hilight color.
   -color: Print the message with <color>. color is in %%code format
           (see docs/formats.txt)
   -actcolor: Color to show in statusbar activity, or don't change if %%n.
   -level: Match only for <level> messages, default is
           publics,msgs,notices,actions
   -channels: Match only in <channels>
   -priority: Priority to use when multiple hilights match. Default is 0.

Examples:

Hilight lines that have "mynick" word:
  /HILIGHT mynick

Hilight all messages from "mynick":
  /HILIGHT -mask mynick!*@*

Hilight lines that were written by nicks from *.fi with bold green
  /HILIGHT -color %%G -mask *!*@*.fi

For regular expressions, see `man 7 regex`.

See also: DEHILIGHT, SET HILIGHT