This textile may have been sewn into the jacket of an American military aviator during the Korean War (1950-53). It's an example of a "blood chit," an IOU for a soldier's life. The first military blood chits were used by the British in World War I in India, though the concept dates to the late 1700s. Still in use today in Afghanistan, blood chits enable pilots shot down over hostile territory to identify themselves and offer a reward for their safe return.
The blood chit shown here, measuring 10-1/2 by 13-1/2 inches, is made from wool felt. The text (in Korean and English) appears to be machine embroidered, and the United States and United Nations flags are appliquéd. It was not a government-issue item and so had no official value. It was one of many types made by townsfolk for sale to military personnel. These "theater made" items found their way into many aviators' jackets and escape kits. Today they are prized for their craftsmanship.
This chit is one of 48 on display in "Fragile Hope: Lifesaving Textiles in a Time of War," an exhibit at the Design Museum at the University of California, Davis, until March 7.