Just use ID Search to find unknown ID's. If your Uniden TrunkTracker uses alphatags and the radio stops on the talkgroup not tagged, then you can press enter to save it to memory and go back later and identify it by programming it with an alpha tag.
What I would like to be able to do is this...Instead of having to program a seperate alpha tag for each ID, program a wildcard, say 48* and have all ID's that start with 48 be assigned the tag POLICE...kinda like i0 for I-Calls. This way ID 48000, 48016, 48017, etc. would all be assigned POLICE tag.