Extra heavy duty?

It's been a couple of decades since I worked in the industry, but for reasons too dull to go into I found myself in a restaurant supply store on Monday. They had the usual gallon jugs of mayo, but they *also* had gallon jugs of "heavy-duty mayonnaise" and "extra heavy-duty mayonnaise." So my question is: what is "extra heavy-duty mayonnaise" even *for*?