RVIA has defined three motorhome classes.
Type A is built on a bare chassis (but includes conversions of motorcoachs which might be a unit-body shell).
Type B is built on a complete van, although some manufacturers might remove some of the van walls.
Type C is built on a cab-chassis or cutaway (cab missing the back wall). SuperC is just a marketing term for a large C built on a chassis with conventional cab instead of cutaway. Most sold as B+ are Type C without a bed over the cab, but some marketers will call a widened B a B+, so you can't be sure what someone is talking about when they say B+.
