A Precancel With A Cancel?

I don't know what the markings are located under the precancel. If anyone knows please share thank you! Jonathan

What you have here is called a dated precancel. This was a requirement for stamps over I believe 7 cents in value after 1938.

There are several types.

There are the integrated dated precancels where the date and the city/state are printed at the same time from one device. There are multiple varieties of these.

There's also what you have. The precancel was applied first and is a separate device. The date was added afterwards and would change with the month/year.

Two of the biggest users of precancels were mail order companies. This is from one of them, Sears Roebuck & Company (SRC). The other was Montgomery Wards (MW).

I've notice both images you've shown us are on piece, meaning they are still attached to part of the envelope. If you have any still on the envelope, don't tear them off the envelope!

Keep the questions and images coming.

Thank you very much for sharing the info. It's fun to learn obscure facts about stamos!