This is a Message Board Post that is gatewayed to this mailing list. Classification: Query Message Board URL: http://boards.ancestry.com/mbexec/msg/rw/7aB.2ACEAE/844.1.1.1.1.2.1.1.1.2 Message Board Post: What you have here, I believe, is a bit different. That space at the back of your photo, was the space reserved for placing an "Internal Revenue tax stamp". There was a time when a photograph was expected to remit a special tax on photos, to Internal Revenue. These tax stamps affixed to the back of a photo, were usually stamped with the name of the Photo Studio or initialled by the photograph, together with a date when the tax was paid. Today, this is a great tool for genealogists to properly identify the exact period a particular photo was taken. You should be able to find on the web, additional information about the history of photography and it's evolution. You'll find there more info about the history of the "tax stamps" and during which period they were in effect.