Certificate of authenticity

A certificate of authenticity (COA) is a seal or small sticker on a proprietary computer program, t-shirt, jersey, or any other memorabilia or art work, especially in the world of computers and sports, it is commonly a seal on paper authenticating a specific art work which and is made to demonstrate that the item is authentic. Computer COAs have a license number on them, which verifies that the program is a genuine, legal copy. Art work or posters come with a certificate of authenticity signed and sealed by a reputable appraiser or auction house.