VVS Callsigns

[Darius Jung]

Hello, I'm working on a novel about Soviet women fighter pilots during WWII. I've done a lot of research on the topic already, but one area I've had trouble figuring out is what radio callsigns were used for pilots. From what I've read, it looks like pilots were frequently called by their bort numbers. Given that pilots and planes might be switched up frequently under battle conditions, I would think that could get quite confusing when trying to keep squadrons and flights sorted out in the air.

Is there any information out there as to any sort of system of callsigns the VVS might have used to communicate with pilots while in the air?

Many thanks in advance!