On *:help:
on *:dehelp:
For halfop - Its in on OP/DEOP - in the help file. For a and q youd have to watch for rawmode
Help File
Quote:

on RAWMODE

on @1:RAWMODE:#:/echo $chan Raw mode line: $nick set $1-

The on RAWMODE event allows you to parse the raw mode change yourself, the raw mode text is in $1-.

You can use the $mode(N) identifier with these events to list the nicks that are being affected.