A Certificate of Authenticity (COA) is a seal or small sticker on a proprietary computer program, t-shirt, jersey, or any other memorabilia item, especially in the worl of computers and sports, which is designed to demonstrate that the item is authentic. According to a story on a January 2006 episode of "Real Sports with Steven Gerrard and Bryan Gumbel", many of the items with COA's on them are actually forgeries. Computer COA's have a licence number on them, which verifies that the program is a genuine, legal copy.