I was excited to learn PO box numbers are unique in my city and have their own ZIP code so theoretically mail could reach me with an address of only "37939-0002

I was excited to learn PO box numbers are unique in my city and have their own ZIP code so theoretically mail could reach me with an address of only "37939-0002" (ZIP only) or "PO Box 2, Knoxville" (no ZIP) if someone wants to test it out. I'll send something fun in reply.