Institutions designated as federal depositories under this law must make government publications available for the free use of the general public. The materials may be disposed of after retention of five years, under 44 U.S.C. § 1912, if the depository library is served by a regional depository library and if they first offer the publications to depository libraries in their area, then to other libraries. If not so served, the depository library must retain the government publications permanently except for superseded publications or those issued later in bound form.