The Mysterious Mr. Z in Z39.50 ;-)

An explainer about what “z” in z39.50 stands for all the confused souls.

27 years back, in 1991, Subhash Ghai released a movie named – Saudagar. The signature tune from its original soundtrack was a song – “ILU ILU.. YEH ILU ILU KYA HAIN? ILU ILU? (‘ILU ILU… What is this ILU ILU?’)“.

In case you are wondering about the context of this song, ever since NECOPAC z39.50 service went live last month, the most repeated common question coming from LIS students and professionals on FB has been – “What does ‘Z’ stand for in z39.50?”.

For some, it is a question that popped up in their head when encountering z39.50 search in Koha. For others, especially from West Bengal, India, apparently this is a question that is being asked at the currently on-going interview for WBHRB.

Some wondered that it perhaps stood for the company that started z39.50, while others had no idea.

So what is z39.50?

In very simple terms Z39.50 is a communications protocol for searching and retrieving information from a bibliographic information database over a TCP/IP computer network. It is covered by ANSI/NISO standard Z39.50, and ISO standard 23950:1998. The standard is maintained by US Library of Congress.

Cataloguers mostly encounter z39.50 when they attempt to do copy cataloging. Copy cataloging is a process of fetching and editing a pre-existing bibliographic record from a z39.50 server instead of creating a completely new record from scratch. Thus helping to save time, effort and therefore money, while bringing in a certain standard in cataloging quality.

Ok! Just tell me what “Z” stand for!

Asking what “Z” represents is actually asking the wrong question. The correct question to ask is What does Z39 stand for?.

The short answer

On its own, Z39 simply refers to the American National Standards Committee Z39. By itself “Z” has no special meaning. In the present context, Z39 refers to NISO standards related to publishing, bibliographic and library applications in the United States of America, all of which start with “ANSI/NISO Z39.”.

Towards the end of this post a few example NISO standards have been listed.

The long answer

To understand we have to look back at the history of standardization process as it happened in the United States of America during the last century.

Exactly 100 years back in 1918, 5 engineering organisations and 3 federal organisations came together to form the American Engineering Standards Committee (AESC). In 1928, AESC re-organised to form the American Standards Association (ASA). In 1966, ASA became the USA Standards Institute, followed by a further transformation in 1969 to become the American National Standards Institute or ANSI as we know it today.

The centenary video from ANSI describes the journey of standardization in United States and its global impact.

It was during the ASA years that formal standardization of librarianship started to take shape.

Image source: The Legacy of a Librarian: Carolyn Ulrich’s Little Magazines

In 1935 Carolyn F. Ulrich of New York Public Library led the initiative to create a standard for arrangement of periodicals that became known as Z29.1-1935.

In 1937, prompted by various library associations, ASA appointed Ulrich to represent ASA on International Standards Association’s (ISA) Committee 46 – an international committee on documentation.

This further led to the organisation of a national committee on library standards in June of 1939. The committee was simply named as “Committee Z39” and was tasked with setting up

“Standards for [library] concepts, definitions, terminology, letters and signs, practices, methods, supplies and equipment.”

Over time it came to be known as the “American National Standards Committee Z39“. In 1984, it changed its name and structure to become the National Information Standards Organization (NISO). NISO today continues to develop, maintain and publish technical standards related to publishing, bibliographic and library applications in the United States of America as an ANSI accredited SDO (standards designator organization). All NISO standards all start with “ANSI/NISO Z39.” (read as zee or zed thirty nine dot).

To cut a long story short, z39.50 is simply the 50th NISO approved standard

Example of NISO standards

If you wish to explore further into the world of NISO standards, please do visit the NISO standards tracker for active standards.

Featured image is from the document “Task Force on American National Standards Committee Z39: Activities and Future Directions” published in 1976. The full-text of this historical document is available here.