There's a handy little app for smartphones called Radio ID which neatly identifies MDC-1200, GE Star, and Kenwood FleetSync ID formats. It also identifies QC-II and similar tone formats. You simply fire up the app and set your phone next to your scanner or other radio. As the tones are transmitted, you note which agency goes with which tones.
I have it running on my old iPhone 5S which I no longer use as a phone. Works great.