I have had a motorcyle license endorsement in 3 different states and it was an endorsement to the regular driver's license. It allows the legal operation of a street legal motorcycle on the roads regardless of engine size. Did not have 4 different classifications only 1. In your state of Tn. looks like the Motorcycle Secondary is the one you need as it covers motorcycles without size of engine restrictions and is in addition to regular driver's license. The Grom is a street legal motorcycle. Some states have engine size restrictions for operation on interstate highways and I think 150cc is the threshold, so the Grom is not legal to operate on the interstate in those restrictive states. We do not have those bogus rules in Florida. Does Tn?