This is interesting. Here is a definition for a WD System that I found on RVHotlineCanada.com:
WEIGHT DISTRIBUTION SYSTEM
A hitch system built around a receiver hitch, which includes supplemental equipment such as spring bar that work to distribute trailer tongue loads to the trailer axle(s) and the tow vehicle front axle. Use of weight distribution system enhances handling and braking and increases trailer towing capacity beyond what is recommended when a weight carrying hitch is used.
Although none of us like the use of "distribute trailer tongue loads", it does in fact end with something along the lines that I suggest.
So far every description that I have found states that a WD system distributes tongue weight or loads.
