I'm preparing a return with Office in Home deduction 20.94% business use.  Client is talking the standard deduction. Thus I can input the numbers directly on F8829, Line 10 & 11.

ProSeries Prof'l software is telling me to use Lines 16 & 17 (Excess) lines instead of Lines 10 & 11 if taxpayer taking the standard deduction. Can anyone explain this to me?