Mobile Home Tires and Axles On Trailers

I wanted to sort out some confusion about what I've learned about mobile home tire and axle use on trailers.It is not the axle itself that you cannot run, it is the tires, IF they say for "Mobile Home Use Only" on the side. the axle itself is a standard 3" tube axle with either a welded on brake attachment flange or a bolt on. They run the same bearings as a Decter 5-6k axle. IF you can point me to an actual law that says you cannot run MH style axles I'm all ears. I've heard all the friend of a friend says they've been illegal since 1972, but no one can point me to a specific law. If it ain't in writing, it ain't the law. I asked our local MSP CVE officer and he was the one who told me that the MH use only tires are what you can't use. The axles themselves are no differant than any other standard Dexter 3" tube 6,000# axle. Any questions, feel free to leave them in the comments below. Thanks.