What does this label on my mail mean?

I recently recieved a DVD from an online movie rental service. It was addressed to my correct current address. On the bottom was a yellow label that had the first letters of my last name, the beginning on my address, what looks like a zip code and the date. Underneath it says:

Return to Sender
No forward order on file
Unable to forward
Return to sender

I moved here a little less than a year ago. When I moved, I filled out a mail forwarding form, and they forward my mail for a while. I think they only do that for a few months. Other than that form, I’m not officially living here and I’m not sure if even the landlord knows I live here. I havn’t had any trouble getting mail, but I’ve noticed that it does seem a bit slow.

Forwarding orders for 1st Cl. and Periodicals last only long enough for the publisher to activate a change of address.

YOU must notify all Periodicals and 1st Class correspondants.

It means that the USPS fouled up and applied a label carelessly but the carrier delivered it anyway.

Is your name on the mailbox along with the renter’s name? My husband is a USPS letter carrier, and if a name he doesn’t recognize shows up as being addressed to a particular address, he might try to find out if that person really lives there (perhaps by knocking and asking). He’s gone for the weekend, or I’d ask him what else he is supposed to do otherwise.

What with the label being there, my best guess is that the carrier (perhaps a substitute for the day) saw a “wrong” name for the address, and had it sent out to be checked for a forwarding order. There was nowhere for the order to be forwarded to, but after that I’m not sure what happened - perhaps it was simply sent back to the route.