Dana,
I recently recieved this response from GBCI:
"If you do not wish to submit the ID credit in
your Design Final review, do not mark the credit "complete" and do
not select it for review when submitting the project within the timeline tab." 
This was a question about design final review, but it also applied to the initial design review. There is no longer a button to defer a credit. Now you just don't mark it complete or select it when submitting for review.
Hope this helps!