You can't do that on Sonyvision

So I'm perusing the company list of restricted words, words that can't be used in our stuff, and there's the usual suspects,
including a few I always find amusing, like "douche" and "douchebag".
You know, in French, "douche" means "shower", so imagine my confusion when I first moved to these United States.

And the very last two words on the list are "zipperhead" and "zipperheads".
I don't think I've ever run into this expression.
What does it mean?