What does Carson Number 322 mean stamped on the back of a picture signed by W A Carson patented June 24 1924?

The Carson Number 322 likely refers to a specific model or type of photographic print or frame produced by W.A. Carson, who was known for his work in Photography and related inventions in the early 20th century. The patent date of June 24, 1924, indicates that the image or technique used in the picture may have been protected by U.S. patent law at that time. This combination of information suggests that the item is a collectible piece of photographic history associated with Carson's innovations.