When ATC points out traffic that is a regional airline (e.g. Compass, Envoy, SkyWest, etc.), do they use the phonetic callsign of the airline, or do they use the callsign of the airline that they are operating as (how the plane is painted)?
The plane that a regional airline flies might be painted differently, depending on which airline they are flying for.
1) Pros of using the "aircraft paint": aircraft who are flying in VMC can spot each other more easily.
2) Pros of using the phonetic callsign: aircraft are on the same frequency in the same phase of flight, so they are more situationally aware if you use their phonetic callsign because they have probably already heard it in another transmission.