Even though these tests are regarding a slide-in truck camper and not a Fifth-Wheel trailer and the hitch mounted on the truck bed required to tow it, this is a news article from Ford regarding usage of the truck for the purpose of hauling (in the case of a slide-in truck camper) or towing (in the case of a conventional Travel Trailer or a Fifth-Wheel trailer) a recreational vehicle.

Slide-in truck campers, conventional Travel Trailers, and Fifth-Wheel trailers are considered Recreational Vehicles, even though they are not motorized.

Ford knows its owners all have different uses for their F-Series Super Duty, which is why the company goes to extraordinary lengths to satisfy as many customer needs as possible.

Source: Camping confidence: How Ford tests all-new Super Duty to ensure truck can handle large slide-in campers | Ford Media Center