Where <l> is a comma separated list of one of the following: CRAP, PUBLIC, MSG, NOTICE, WALL, WALLOP, NOTE, ALL, or NONE. This controls what types of messages will go to the current window.
No information is ever lost. Anything that doesn't otherwise have a specific window to go to (because it is a window's current channel or QUERY user) will either go to the current window, or the window whose LEVEL setting contains an appropriate type for that message. By default, the first window created has a LEVEL of NONE, meaning that no messages will go to that window unless otherwise specified.
Output from NAMES, LIST, WHO... fall under the CRAP category for LEVEL. If you want, for example, these messages to always go to the current window, you can type this:
WINDOW LEVEL CRAP
Now, all "crap" will remain in this window, while all private messages,
walls, wallops, mail, and notices will go to your current window.
See Also:
set/lastlog_level for a full description of the LEVEL parameters.