Yea there is some ambiguity in the instructions. The instructions for lines 7 and 8 of Form 1120S, the key words are "...reported elsewhere on the return...". I took that to mean that if you reported the 401k elective deferral on line 17, don't also report it under line7/8. And then Line 17 also uses the same wording "Enter the deductible contributions not claimed elsewhere on the return...". I took it to mean if you place the contribution on one of the lines, don't also include it on the other line. But from my interpretation, I would come to the conclusion that one could put the 401k employee elective deferral on line 7 or line 17.
