What universities (especially in the USA) prohibit or restrict duplicate advanced degrees?
This is more of a statement of how resources are allocated than a strict prohibition. It is a statement of "may enroll", rather than one of "may not enroll". I think admissions committees at a lot of places take a similar view, even without a formal statement. "Why do you think you need a second math masters?" 

The available slots and money are limited most places and committees generally want them to be be used to expand the pool of educated folks. 

So, I think that any numerical answer will be misleading. And any listing would be equally misleading. 

But the statement is useful as guidance to those who would want to apply when it would be unlikely that the committee would accept them.