That's right, but it's not a verification number. It's a transfer authorization number because, on restricted and prohibited firearms, every time there's a transfer, there is an investigation into the individual. Then the transfer authorization number is issued saying that the transfer has been completed and this is the reference to the background checks and everything. Then there is the actual registration number, which is a different number. They are all different from the serial number.
On May 24th, 2018. See this statement in context.