It is also used to identify variant implementations of a format. Arrangement of the List Entries in the list are arranged in alphabetical order by the code and consist of the source code followed by the bibliographic citation for the source work.
Source codes consist of a maximum of eight lowercase alphabetic characters.
The code may be followed by the edition or date of publication of the source work. Omission of the year or edition will imply that the assigning institution used the most recent edition of the source work available. MARC Code Lists for Relators, etc.