I just read the procedures handbooks for two different Angel Flight
organizations and noticed that one recommends the call sign "Compassion"
and filing flight plans with the identifier "CMFxxx" and the other,
"Angel Flight" and the identifier "NGFxxx."

Having heard "Angel Flight xxx" for years I was surprised to learn the
"Compassion" term apparently has been around since 1999. Neither seems
to be mentioned in the AIM; "Lifeguard" is, but that is a different
operation (air ambulance).

Any particular reason for multiple terms other than different
organizations marching to different (possibly politically correct) drummers?