note <command> [+|-<flags>] [<arguments>]

The NOTE command is a historic irc server command (meaning this help file really belongs in section 3). You would be hard pressed to find a server that supports the NOTE command. As of mid-2001, only the undernet servers even come with the NOTE system, and it isn't turned on by default, and it isn't even a configuration-time option.

A meaningful discussion of the NOTE command is beyond the scope of a mere help file. There never really was any good documentation for it anyways.