This is a Bermuda WWII Registered Cover that was sent from Mexico to St. Gall, Switzerland on 1/29/1941.

This cover has the Bermuda Censor 6081D tape, along with Bermuda Registration Number 1466 in Red on the back.  This is an early 4 digit BRN, and it was superseded by the 5 digit BRNs later on that same year.