I have a rough idea of where I want a hole in the part I'm making, but I don't want to nail it down quite yet.
I'd like to make a geometric shape that is fixed(or somehow constrained to other features), and tell a modeling software that the feature I make has to be within that area.
I could then make final decisions for the locations after the manufacturing people have had a chance to look at it, and select the locations based on cheap manufacturing.
This is similar to GD&T, but I'd like the CAD program to be able to have things float arround a bit
An example I had was I didn't care what angle a certain hole was drilled, it just had to meet another hole... It turned out that I should have designed my part about a cheap readily available drill bit. (actually, I figured that out really early, so there were no problems)