Catalog Unsubscribing

I make it a routine task to request removal from any and all catalogs that show up in our mailbox. Sometimes there is a bit of detective work to get removed from them, they don't go out of their way to make it obvious. This made me wonder why email is required to have an unsubscribe method clearly displayed while catalogs and regular mail don't have any requirement.

There should be a requirement for unsubscribe information to be presented plainly and near the mailing label. In fact, how about a URL printed for each mailing address that unsubscribes that address? Heck, I might even use a QR code for that!