donor card
From Longman Dictionary of Contemporary Englishdonor cardˈdonor ˌcard noun [countable] a card that you carry to show that when you die a doctor can take parts of your body to use in the medical treatment of someone elseExamples from the Corpusdonor card• Six-year-old Stewart Davies carried a donor card everywhere with him, heartbroken dad Brian revealed.• Remember, by filling in a donor card you could help save some one's life.• Only two weeks before, she told her mum she wanted a donor card in case anything happened to her.• I therefore launched the donor card again last week.