The Leader is the first field of a MARC record.  It is fixed in length at 24 character positions (00-23).  The Leader consists of data elements that provide information for the automation system processing the record.  The data elements contain numbers or coded values and are identified by relative character position.

While the Leader contains much information that is system supplied, users do have access to some of the character positions for coding purposes.  For example, in the bibliographic data format, the user can identify the type of material being cataloged, such as map, musical sound recording, or projected medium, by entering a specified code in the Leader/06 position (Type of Record).  Most of the system-generated elements in the Leader represent MARC structural information.

For information about the Leader in a specific MARC 21 format, select:

Leader  (Authority)

Leader  (Bibliographic)

Leader  (Classification)

Leader  (Community Information)

Leader  (Holdings)

For return, select:

Elements of a MARC Record

Components of a MARC Record

A General Introduction to the MARC Format