For example:
!say hello | quit
That will make you say hello, then quit.
That won't happen, Riamus2. The pipe ('|') would be interpreted as a line separator only if you used a script like this:
on mylevel:TEXT:!say*:#:{ scid -r msg $chan $2- }
; or: on mylevel:TEXT:!say*:#:{ .timer 1 0 msg $chan $2- }
Leaving $2- as it is there is safe.