Squires doctrine is a rule of the U.S. Patent and Trademark Office that a utility patent claim can incorporate drawings or tables by reference, only when there is no other practical way to express the information in words. It can also be used when referring to the artwork as a concise way to communicate the information. It is allowed only when necessary, and is not available just for the convenience of an applicant. The standard was set in the case, Ex parte Squires, 133 U.S.P.Q. (BNA) 598 (Pat. & Trademark Office Bd. App. 1961) where it was held that claiming by reference to a pictorial representation is proper where reference to pictorial showing of outline of object sought to be covered by patent is the best, most accurate way of defining the invention which depends for its utility on precise configuration of numerals and their interrelation in a set.