MARC Control Fields

Control fields are the group of coded fields that appear like strings of characters at the top of a MARC Record. For many new and seasoned catalogers they can be a little intimidating or seem overly technical, and that’s completely understandable—after all, these fields are meant to be interpreted by machines, not humans. But it’s important that catalogers have a basic understanding of how control fields work because they influence some pretty important functions, including how resources display in the discovery interface.

This video tutorial, MARC Control Fields, provides a high-level overview of how control fields are constructed, describes how they relate to one another and to the descriptive fields in a MARC record, and suggests specific elements within each control field to focus on when you are cataloging.

This video is sixth in the ongoing Cataloging Fundamentals video series, one component of the Cataloging Fundamentals Program. If you have ideas for a future video or about how to support new catalogers in Colorado, please drop me a line at

Amy Hitchner
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