As of August 1, 2004, GPO is assigning SuDocs classification numbers to all online-only Federal Government monographs in accordance with existing policies for tangible government monographs. The previous policy was to use a machine-generated record control number as the suffix after the class stem. Serials were not affected. The new policy, requested by depository librarians, replaces the control number with a Cutter or series number, as appropriate to the material.
At this time there are no plans for any retrospective conversion. However, the older numbers will be changed when a revised edition is issued, and for titles of high historical importance.