MD TAC 10 has been active for the past few days with activity that sounds routine rather than a tactical use. The dispatchers and users sound "semi-professional" and sometimes hard to understand. Anyone have any clues what agency is using? Also one user / dispatcher using a five digit RID 99012 instead of a normal 7 digit pattern. Units are ID'ed "Car-xx." Heard on AA site, and MD TAC 10 is supposedly the Western region.