So, with Forest Roads we’re supposed to do the ref tag is like “FR 143” but the forest service just refers to it as 143 in their information.
What about other agencies that managed roads on public land?
IE, Bureau of Land Management (BLM) manages National Monuments and other roads on BLM land. Are the ref tags for those roads still prefixed with “FR”?
How about the National Fish and Wildlife Service roads managed on public land?
Use of 'BLM" as a prefix is well established (put ‘BLM’ into the search box under ‘Values used with this key’ on https://taginfo.openstreetmap.org/keys/ref#values to see how it is used). I’m not sure there is anything widely used for Fish and Wildlife.
Note that ‘FS’ is also in wide use for forest service tracks, with FR used for roads that the forest service calls Forest Roads, like on https://www.fs.usda.gov/recarea/giffordpinchot/recarea/?recid=66099 .