Under the Schedule D "Capital Gains and Losses Condensed Entry Table" you'll find Misc Options selections A and B. If you select Yes under Option A, you'll always print the Form 8453. The sentence within the parentheses explains to mark Yes only if you're going to attach paper printouts and mail with the Form 8453. Conversely, if you're attaching PDF's to the efiled return, do not mark Yes. That should keep the 8453 from printing. At least that's the way it works on my system.