Each separate piece, such as a folder, binder, etc., should have its own separate class number written on it, so that it may be identified when separated from the basic publication. The class is added to each piece solely for identification of stray pieces, and not for cataloging purposes. Spacing The format of the Superintendent of Documents classification number is critical for the proper construction of the number itself and for accurate sorting and searching of class numbers in automated systems. One important aspect of the construction of the class number is the use of spacing. A space must be inserted between letters and numbers in the class number unless there is intervening punctuation.
Parentheses are the only exception.
One space must be inserted before and after a parenthesis, unless there is adjacent punctuation. Class Number A classification number may have as many characters as can be input in the 099 field of an OCLC record. The current limit is 47 characters. All letters in Superintendent of Documents classification numbers are capitalized. Prior to September 1992, a combination of upper case and lower case letters was used.