We all know the marshaller signals. Go left, go right, stop, death threat, etc.

There is, however, one that appears in official docs, but never in discussions or at the airport (at least I’ve never had a marshaller show this to me) – the “dispatch aircraft” symbol:

Does anyone know when this is used, if at all? The definition (“Perform a standard salute with right hand and/or wand to dispatch the aircraft. Maintain eye contact with flight crew until aircraft has begun to taxi.”) suggests that it’s supposed to be used after you obtain taxi clearance but before you start to move.

That said, the marshaller has never been present when I was getting ready to taxi. I always just called tower or delivery to get startup and taxi clearances, switched on the taxi lights and went on my merry way. So, what’s the reason for this hand signal’s existence? And how would the marshaller know when to dispatch the aircraft since (I assume) they aren’t listening in on radio? Is it only used in commercial or military aviation? I know it’s a standard thing on aircraft carriers to confirm the pilot is ready for takeoff, but this signal is featured in ICAO docs, not US Navy procedures. Has anyone here been saluted by a marshaller? Would love to hear your answers.