This machine-embroidered cloth arm patch was worn around 1944 by a US Navy Specialist I, Third Class. Navy Specialist is a rating that refers to an enlisted sailor's job specialty and the letter I inside the diamond indicates that the sailor who wore this patch had been trained to be a machine operator for a punch-card accounting machine, an electric accounting machine, or a tabulating machine. The single red chevron below the diamond indicates that the specialist's rate, or pay grade, was equivalent to that of a Petty Officer Third Class.
Grace Murray Hopper (1906-1992), a mathematician who became a naval officer and computer scientist during World War II, donated this patch to the Smithsonian. Hopper joined the U.S. Naval Reserves in December 1943. From July 1944 she worked with the Navy’s Computation Project at Harvard University’s Cruft Laboratory writing computer code for the Mark I computer, formally known as the Automatic Sequence Controlled Calculator.
Similar patches (with white background) are shown on World War II images of specialists working on the Computation Project. Hopper herself had been commissioned a lieutenant (junior grade) before she was assigned to the project, so she would not have worn this patch.