I think identifying the airline you work for is a mistake. In this internet age, one can easily find posts used against them and lose their job.
It is hard to know if someone is bluff or real. I met a fellow on this site who actually knew someone I knew...and knew enough about them that I have no doubt about their flying background.
There isn't a secret handshake or anything. But I can usually spot a phony.
There are questions one can ask...''in jokes'' hotels that aren't there anymore that can really identify someone.
Ask an old USAIR East pilot what the hotel's name was for the overnights in KBUF...anyone might tell you...but when he smiles, you will know.
Ask an American pilot who CR was and see how many tell a canadair regional (ha!!!!!)
I could go on, but won't.