Linking to Library Resources: Z39.50 Access to the Catalog

Z39.50 (z3950) is a protocol. It is also a NISO standard, developed by the library community and used to create a client application that allows users to search and retrieve records within a bibliographic database. Z39.50 was originally developed to allow libraries to search each other's Integrated Library Systems (ILSs), even when they were provided by different vendors. In the past few years, the use of Z39.50 has been expanded to access Abstracting & Indexing (A&I) databases as well as full text resources. 

The Z39.50 client application may take the form of a standalone program, or it may be a web gateway. With Z39.50-enabled web gateways, the library can create their own web interfaces to library catalogs and databases. 

The US Library of Congress provides the following document on the Z39.50 protocol and application service definition:
https://www.loc.gov/z3950/agency/Z39-50-2003.pdf

Many applications can search the library catalog using this protocol. Examples include citation managers such as Zotero, Refworks, and Mendeley. Interlibrary Loan applications such as ILLiad can also search the catalog using this protocol. A standalone Z39.50 client such as BibDataZU can search single or multiple catalogs with a list of titles or ISBNs using Z39.50 and retrieve MARC records for cataloging and other uses. For example, running a list of scanned ISBNs against the local catalog can quickly determine if bibliographic records exist for those titles.

Z39.50 access requires the following information:

• Server address: catalog.carr.org
• Port: 210
• Database name: CCPL.PAC
• Record syntax: USMARC