This report reviews the background and rationale for a cooperative authority file building system and describes the services, products, and operation of the new Name Authority Cooperative (NACO). The document defines the relationship between NACO, other Library of Congress (LC) cooperative projects, and the Linked Systems Project (LSP). The document comprises: (1) a brief description of how the NACO service will be operated by LC, including what will be included in the NACO name authority file, how various types of libraries will contribute to the file or use the records, and how LC will manage the project; (2) delineation of the factors that will be considered in selecting libraries to participate in the ongoing maintenance of NACO; (3) a description of the quality review procedures and standards that will be applied to records; (4) a description of what still needs to be done before NACO begins to function, and an outline of the relationship of NACO to LSP. Appendices include: a report from a 1979 meeting that presents the background and rationale for the project; revisions of the "Requirements Statement for the Name Authority File Service"; results of a survey conducted in 1982 to ascertain the likely use of such a service and the features that would be most useful; and a glossary. (THC)