24.21D.
Add the number and year (or the number, session, and year) only to the heading for the U.S. Congress. Use such a heading only if the item meets all the following conditions:
1. An added entry must be made for the U.S. Congress as a whole or for one of its chambers;
2. No main or added entry is appropriate for any committee, subcommittee, or other subordinate unit of the U.S. Congress as a whole or of one of its chambers;
3. The number of the session is named in the chief source.
See also: