I'm not sure what the difference between tolerance and oversize is.

[LeeJaeYoung]

I'm not sure what the difference between tolerance and oversize is.
When installing the door, make sure to leave 10mm of space on the top, bottom, left and right of the concrete wall beyond the size of the door.
So is this tolerance? Is it oversize?

[Miha_M]

Essential difference: Entering an Oversize does not (unlike the Tolerance value) affect the Nominal Size of the opening. For further reading the Help pages also have some descriptions about this topic: Nominal Sizes and Tolerance (graphisoft.com)

Solved: Doors: Tolerance vs Opening Oversize - Graphisoft Community

The above link gives you some explanation about this. I am using the GER localization library, where both terms are one and the same thing - a raw wall opening size.