In SOL 200 Nastran Optimization there is an option for design response stress for CQUAD4(33) element using stress item code 9 which indicates Von Misses stress. However, in the results file .f06 under the design response column for the value max. principal stress is given.

Strangely for CQUAD4(144) corner output stress item code 9 indicates max. principal stress.

So my question is how do we distinguish CQUAD4(33) and CQUAD4(144) in the input file.