Right now, we can't have two sheets with the same number in one file. But what if we want to have multiple sets in one project (one for Construction Documentation and one for Filing for example). In a lot of places numbering conventions are strict so we can't just add a prefix or suffix.
I'm proposing we get a warning when there are duplicate sheet numbers, but we can accept the risk (the same as with duplicate type mark values).
We have two projects running now that each have 4 filing sets, one CD set and a few presentation sets. All of them have to have unique numbering, which means that we had to split it up in 5 files. Also, I'd like to number my presentation sheets as 1, 2, 3, ... instead of presC-1, presC-2, ...