Accession Number. A registration number employed by museums to identify newly acquired items. Formerly, museum registrars or curators would apply such numbers with paint or India ink or otherwise mark the accession number on the edge or reverse of a medallic or numismatic item, although modern museums now consider the practice defacing the objects. The accession number remains permanently on the item while the property of the museum. Should the item ever be sold, or deaccessioned, the number is usually not removed, and such items have been observed in the numismatic market that have passed through several hands. (In one case, a medal purchased with one museum's accession number has been donated in a collection to another museum.) Had the item been stolen from the museum it is, of course, an obvious indication of ownership. Most such accession numbers can be removed professionally, but in the process the original lacquer, if any, is destroyed and the piece must be relacquered. Compare collector’“s mark. See also numbering system.In the 21st century many museums have made a listing of their holdings available on the internet, usually with illustrations. Since the accession number identifies each specimen, the knowledge of this number can enable anyone to obtain the illustration (and often the description) of the specific specimen. Their entire holdings of medals and most all coins are on the American Numismatic Society’“s internet site. These can be accessed by accession number or keyword in the description. CLASS 11.3 Illus: SoM #83.
Source: D. Wayne Johnson Encyclopedia of Coin and Medal Technology