Today, the Library of Congress announced an expansion of its LCCN Permalink Service for the Library's name and subject authority records. These persistent URLs are based on the Library of Congress Control Number (LCCN). As with bibliographic records, LCCN Permalinks are displayed on authority record entries in LC Authorities.
Information regarding how they work, how to create them, and other additional information on this service is available on the LCCN Permalink FAQ. Specific questions can also be sent to the Library of Congress through Ask-A-Librarian.