I agree with Burner50. Up here in the northwest corner, there doesn't seem to be any county-wide system. Some counties do use numbers, but others just use the name of the truck, like "Little Rock Pumper" or "Lester Tanker." It's much more on tradition. Some of the personnel have numbers. Like the the George, Iowa Fire Chief is "GF-1A". I don't know if the rest of the officers have numbers or not. The Rock Rapids Chief is "F1A." The numbers go down with the rank. Like Assistant Chief is F1B, then there's also F1C and F1D. "F" obviously stands for "Fire," but why the number "1" and then a letter, I don't know. The rest of the chiefs in the county just go by "<town name> chief." In Orange City, I know their trucks are all 84-6X like 84-sixty-three, etc. But there doesn't seem to be any rhyme or reason to it and even less with other communities in the county. I know Sheldon's ladder truck's number is the same as an aerial truck that FDNY lost, as a tribute to that aerial company. It's just a total mixed bag up here, unlike law officer numbers, which, for the most part, are a coherent system in most parts of the state (except for large metro areas where everything is different.)