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:

24.21. Legislative Bodies