Establishes the history attribute for the element. If an element has the history attribute, its history is included in the file when you retrieve it with the FETCH or RESERVE command. The quoted string specifies the format of the history. The quoted string must contain the characters #H or #B (lowercase is allowed) and can contain other printing characters. To include a quotation mark in the output history string, type it twice (""). To include a number sign (#) in the output history string, type it twice (##).