Even though pilots will have their own callsigns, I believe that during large fleet operations we will want to attach specific callsigns to ships performing specific tasks. Since pilots can trade ships, borrow ships, and steal ships, a fleet members role can change from week to week, depending on what is needed for the specific op. To cut down on confusion I came up with a partial list.
Looking Glass - This callsign would be assigned to the advanced radar platform feeding data to the Command & Control (C&C) ship (i.e. the Hornet "Tracker" pilot).
CAG (Commander Air Group) - This callsign would be assigned to the person coordinating ships from the C&C ship
GALACTIC 1 - This callsign would be assigned to the CEO as a single pilot or assigned to any vessel transporting the current CEO.
MED 1 - This callsign would be reserved for the designated Medical Ship
(A callout to Med Group would indicate you are communicating to all Medical Ships)
Marine 1 - This callsign would assigned to the primary assault team commander
Hercules 1 - This callsign would reserved for the lead transport ship (i.e. the person overseeing all transports in a convoy) (a call to "Hercules Group" would indicate that you are communicating to all freighters)
Shadow 1 - This callsign would be assigned to the lead Stealth Fighter (i.e. Hornet "Ghost")
(a call to "Shadow Group" would indicate you are communicating to all stealth fighters)