My grandfather gave me this year's ago. I was told it was instructions in Chinese asking for aid if his plane was shot down. It was a patch on a flight jacket. Can someone confirm/elaborate? https://imgur.com/a/vLyIf
It's a WWII-era "blood chit" - asking for aid, and a promise for payment if the downed airmen was aided and returned to the American military. The exact text varies depending on the patch.