Zephir, the HathiTrust bibliographic metadata management system, is managed by CDL’s Discovery & Delivery team. In this advice column, Barbara Cormack, the metadata analyst for Zephir, answers common questions for contributing records to Zephir. While these questions were written by fictitious authors, you are welcome to submit your questions to Zephir (email: [email protected]).


Dear Zephir,

What exactly are you? Who works on you, and where? Are you one of those AI bots?

– Skeptical Sleuth


Dear Skeptical,

I appreciate this opportunity to do one of my periodic introductions. Zephir is the HathiTrust Metadata Management system. In the early stages of HathiTrust, its records were loaded into the University of Michigan’s ILS. As the collection grew, this approach began to tax that system, so HathiTrust contracted with the University of California via the California Digital Library (CDL) to create a new and separate system to store the records. Zephir was implemented in 2013, and currently stores more than 24 million records, though only those with digital content appear in the HathiTrust catalog. The Zephir team, situated within the Discovery and Delivery program at CDL, is composed of three software developers, a metadata analyst, and a product manager. The team is based in California, but works closely with colleagues and counterparts at HathiTrust. No bots yet, but the team is experimenting with AI models for a variety of purposes, including improved record matching. 


Dear Zephir,

I often take advantage of the “HathiTrust MARC record” button to view records that way . What can I say–I’m a big fan of the MARC format. I noticed that some of the fields contain what look like system identification numbers, but they’re prefaced with “sdr” - for example, “sdr-nrlf.b168400728”. What is that? Does it mean something significant?

– Curious in California


Dear Curious,

You have an eagle eye! The “sdr” can show up in a couple of places in HathiTrust records. It stands for “shared digital repository”, and is a leftover from the pre-Zephir era, when records for HathiTrust were ingested in the University of Michigan’s Aleph ILS, and shared space there. An artifact of Zephir’s history!