I have a question regarding Unit ID numbers. Here in Hamilton I have always heard the state troopers beeing addressed with an A then number on the radio such as A-242 but for the past couple of days I am hearing a new ID it is HP plus number such as HP-35. At the post in Quad Cities they are still calling the A + number. Anyone have any idea what this is. Just a note they are using the A Prefixes too.