The National Preservation Program Office of the Library of Congress is building a collection of audiovisual sources produced in the United States and abroad. The collection comprises films, videotapes, 35 mm slides, and magnetic tapes, and represents a variety of approaches to the care and treatement of library and archival materials. Each entry consists of the title, producer, place and date of publication, type of material, length of the presentation and a brief description of the contents. Criteria for selection include; overall accuracy of the information, general usefulness to the library and archival preservation - conservation community and technical quality of visual images and sound. Organizations and institutions in the United States may borrow materials for up to two weeks. The list, as of 1983, comprised 10 items.