Can be signalled at any apparent time, but is used most effectively to acknowledge a positive action, or something which a pair or large section of a group found amusing.
The phrase is to be used while partaking in the 4 signal (outstretching one arm away from your body and moving it back, forth, back and forth -- until the arm has moved 4 times), stating the action by name as it is performed.
Individuals who are experienced in signalling 4 will almost certainly develop a personal technique, renowned amongst their peers.
It can be used in 2 different scenarios:
1) Stated while performing the signal in appropriate situation.
2) Typed in bold letters in any chat (Facebook, MSN, text) if face-to-face conversation isn't available but a situation is deemed appropriate.
1) You mean, he just shouted at someone in their car, and they turned around, parked up and threatened to kill him?!
Signals 4! (Then instantly performs signal)
2) FACEBOOK CHAT
- So we're definatly on for Saturday?
- *Signals 4* -- at this point, the person may choose to actually perform a 4 signal on their own, entirely preference.
(*'s indicate bold writing)