Well it's a little more than that, its main purpose is to allow for the use of identifiers in the match text and channel sections of events.
/help $(...)
on *:TEXT:$($me):#: { }
on *:TEXT:*:$($mychans): { }
alias mychans return <chans>
Replace <chans> with a channel or channels separated by a comma.
~ Edit ~
Also, $evalnext is not in the help file.
