I'd even settle for a 'reasonable' way to do it, for that matter.  What I am suggesting, specifically, is a pattern of slot features equivalent to that of holes on a bolt circle, for example.  The problem, of course, is that there is no true, single standard for a slot callout, and you can't really turn a "2X R" into anything that conveys the idea of multiple identical slots.  "4X R" or "2X 2X R" are the obvious responses to that, but terrible and not what I'm looking for.