Is sticker paper HIN legit?

Just a footnote to my last post:

From personal experience, I have submitted the bill of sale for a purchase to the appropriate Illinois state agency and have received a Illinois title along with the proper documentation/registration sticker after filling out the required paperwork and paying any necessary fees and taxes.
Once I had trouble getting an Illinois title and registering a pop up camper I bought from a couple in Wisconsin. Wisconsin does not title campers. I got a form letter requesting the title. I had to write a letter explaining the Bill of Sale was all I had, but I did get the problem straightened out. It can be annoying dealing with lack of titles, but it is not a deal breaker.