Bibliographic Cataloging: General MARC Field Policy 856 – Historic URLs

Historic URLs

By request of Federal depository libraries, GPO provides the original URL (known as the “historic URL") used to create the PURL in an additional 856 field, which serves only as a reference in a catalog record. LSCM does not maintain, change, or update historic URLs. With a possibility that URLs may change over time, the GPO PURL is the means of providing access to the resource represented by the bibliographic record.

In older records, the historic URL may also be found in a 530 Additional Physical Form Available Note or 538 Mode of Access Field. These historic URLs can be helpful for locating copies of documents on archival websites (for example, WayBack Machine, NARA, etc.) and should not be removed from records.

Regarding URLs with domain names other than .gov: If possible and readily accessible, record the .gov (i.e., Agency site) as the URL. If not, record the redirected (i.e., hosting site, or .com site) URL.

Add the public note, Address at time of PURL creation, in subfield z of the 856. Subfield z precedes subfield u.

When subsequent parts or issues of multipart monographs and serials, or, additional formats of resources are published, no URLs are added to the bibliographic record. 

GPO practice: When subfield 3 is present, subfield z precedes subfield 3.

CGP 1017660 

Rocky Mountain Arsenal National Wildlife Refuge, fishing permit and regulations

856 4_ ǂz Address at time of PURL creation ǂ3 Current edition only ǂu