The Andy Warhol Authentication Board will be disbanded in 2012. Works authenticated by the board prior to 2012, will be described as such with documentation. Works that include The Andy Warhol Foundation as part of their provenance, are often accompanied by a certificate that authenticates it as a work stamped by the board. Unique works are often stamped with UP numbers, known as Unpublished. This usually means each impression is unique, and there was never an edition.