I’m digging these Women Cryptologists of World War II Stamps.

During World War II, some 11,000 women labored day and night, helping to process and decipher an endless stream of enemy military messages. Their work was by turns frustrating and exhilarating—and one of the conflict’s best-kept secrets. With this stamp, the U.S. Postal Service honors all of the women cryptologists of World War II, whose service played an inestimable role in the Allied victory.