I was listening to Caroline County Station 100 (Federalsburg) doing some fire training on the scanner last night. They were testing out the emergency button on their Motorola digital radios for a Mayday scenario. They were operating on CF TAC-2 for training. The officer in the house hit the emergency button and the radio transmitted on TG 25698. Caroline dispatch was then able to talk to the officer on this TG but no other radios could hear that TG except the activated radio and the dispatch center. Dispatch had to relay "officer down" to Command on CF TAC-2. Is this a universal TG for the UES Consortium or does each agency have its own "Mayday" TG? I did not see any descriptors for this TG.