If you have or get any NFA firearms or items,

you'd better keep every scrap of paper and every electronic record around. Just in case.
Yesterday, I received, as part of a VERY old FOIA request, a “Firearms Inspection Worknote”. While the BATFE denied the existence of any such documents, I knew that these forms existed from BATFE audits of dealers’ inventories. For some unexplained reason, the document was sent along with a letter stating that 290 other similar documents had been found and whether those documents would be of interest.

Of particular interest, on this one heavily redacted “Firearms Inspection Worknote”, at least two of the firearms were in the dealers inventory, but “not listed on the inventory list provided by the NFA branch.” In the second box, the agent apparently wrote in, “F4 [likely meaning Form 4] apvd [likely meaning approved] 8/7/01.” Thus, in all likelihood, the agent was presented with the approved Form 4 while doing the audit, even though the NFRTR either showed the suppressor as non-existent or registered to another person.