Guys, I feel you are unnecessarily creating anxiety for yourselves...
A lot, if not most, of people had PD\'s blank in the receipt notice and have gotten approved. That is definitely not a cause for concern nor the reason for delay. This would be a possible problem if they processed by PD. But, they don\'t. They process either by RD or ND/WAC.
Even if it is not printed on your receipts I am sure it is on the system. How am I so sure? I had blank PD in my I485 receipt but my I485 approval notice had the PD in it. But, the receipt date on the approval notice had my ND in it. Go figure! Don\'t worry on account of missing PD.