Vertical Metrics redundancy

Nick Shinn

What if your typeface has ascenders the same height as caps?

How about x-height: what if your typeface is all caps with both cases identical?
Is there any problem with entering the same value in each field? Or leaving the x-height/ascender value blank?

André G. Isaak

I wouldn't leave it blank — I wouldn't be surprised if at least some development tools treated blank as zero, and you definitely don't want these to equal your baseline. I've frequently assigned all three the same value without problem.