Outgoing Wire Transfer - Physical Address Required

Why is it that most banks that originate outgoing wire transfers require a physical address (no PO boxes) for the beneficiary? Is this a compliance requirement and if so, where is it established? I have looked at Reg J, the UCC, the BSA exam manual and the travel rule without much luck. The latter proved more helpful than the others, but still offered little justification for the requiring of the beneficiary's physical address. In this regard, the rule states that the originating bank is only required to retain "beneficiary information provided by the requestor" which may or may not include an address. Any help in determining how and/or why this no "PO box policy" was derived would be greatly appreciated.