Talkgroup alpha tags

[chrizby]

Where do you get the alpha tags for the talkgroups? I can get some idea of what group these guys belong to, but overall its very difficult to determine who is who from the very limited context in the messages I hear on the scanner. Are we waiting for someone on the inside to tell us the actual name of these talkgroups, are we guessing, or what? Are these alpha tags coming from the control channel? I don't think so but who knows, I have only had a scanner for 4 months.
These are examples for the Kentucky Derby, but my question is more of a general talkgroup nature.

601-01 A DRBYFESTOPS Derby Festival Operations Business
601-2 A FestElectric Derby Festival Electricians Business
601-5 A Marque Vilge Churchill Marque village Business
607-4 A Fest Admin Derby Festival Admin Ops Business
607-5 A Fest-a-ville Fest-a-Ville Ops, Waterfront Park, Derby Festival

Here is some info from a log file.
07:44:30, 0712, TGRP , 602-02, 602-02, TSYS=0356, RCS , AN, 860.112500

07:44:52, 0713, TGRP , 605-00, 605-00, TSYS=0356, RCS , AN, 856.112500

07:45:18, 0713, TGRP , 605-00, 605-00, TSYS=0356, RCS , AN, 856.587500


Just curious.

[rdale]

If someone knows the "official" alpha tag it gets posted, but you can pick whatever you want. They really only matter to the person reading the radio. My local FD's tag is LFMAIN because they have to fit in 8 characters, I set it to LFD MAIN instead.