Almost certainly mentioned before but I'll toss it on here since it relates to a previous request around communications by flight members.

Flares: Red Green White. Attach a flare event (and optional text message) to pilot or player leaving formation, or a FC issuing the RTB or rejoin order. I believe the game codes pilot states (e.g. returning to base, searching, on patrol, in transit, etc) so this would be a visible manifestation of a change in those particular pilot conditions