Forums Scripts & Popups Triggering events properly

How do you allow for:
!youtube - to trigger alone
!youtubelolol - not to trigger, but still let
!youtube This is my youtube! - trigger?

on *:TEXT:!youtube*:#: {
on *:TEXT:!youtube *:#: {

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And how do I define the difference between
!announce1
!announce2
!announce3
without being able to do $2 (not separate word) and having
on *:TEXT:!announce*:#: { triggering on everything that starts with announce.

Cheers!
Cheers!