The Twenty-one-cent Prexie
Sheet stamp use
This registered penalty cover was sent by the Post Office Department in January of 1941. Since it was sent from Washington, D.C., no postage or registration fee would have been payable if it had been classed as official business. Since it apparently was not in that category, both would have been collected.
At the time the combination of postage and fees could have been three cents postage and eighteen cents for registry for $5.01 to $25, or six cents postage and fifteen cents for registry for up to and including $5.