USFS LEOs
I often hear the law enforcement officers on the Ops net (168.75000 Repeater, 170.50000 Input) and Admin net (168.15000 Repeater, 171.38750 Input). I don't believe that I have ever heard them on the service net. Law enforcement officers will have a call sign of "Edward" and then a number, for example "Edward 7".
There are other call signs such as "C" for a special agent, "L" for patrol captain, "K" for canine, and "T" for training. On the Stanislaus, these call signs are much less common that the "Edward" units and some, such a "K", may never be heard at all.