Those are model & floor plan designations and unique to each manufacturer. They may even change the meaning from year to year, though typically differences are small.
You just have to look at each manufacturer's web site and try to find their brochures for previous model years so you can see floor plans and pictures. I know that Winnebago and Fleetwood & American Coach have them online. Probably others too.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL