Leader Field

MARC records in the Innovative system use a LEADER field to store information about record length and structure.

Each MARC record can contain only one LEADER field, which is a system-generated variable-length field that uses no indicators or subfield identifiers.

For a detailed description of the leader field in MARC records, see the MARC Standards publication by the Library of Congress. In general, leader fields are 24 bytes long (byte count 0 through 23). The first five bytes (0-4), right justified with zero fill, represent the logical record length. The record length includes the five-byte record length and the record terminator. Bytes 12 through 16 (from offset 0) contain the "base address," which specifies the first character position of the first variable length field, and is equal to the sum of the lengths of the leader and the directory, including the field terminator at the end of the directory. This number is right justified with zero fill. (The base address minus one is evenly divisible by twelve.) Below is an example of a leader from a bibliographic record for a musical sound recording:

02096cjm 2200457Ia 4500

Because the LEADER field contains important information about the record itself, many elements of the field are protected and some are masked from view, such as RECORD LENGTH and BASE ADDRESS. However, you can edit some of the elements of the field and have your changes validated by the system.

To view and edit a LEADER field:

  1. Retrieve a bibliographic, authority, or checkin/holdings record.
  2. Choose Edit.
  3. Click the LEADER field.
  4. Choose Edit | Expand Field.
  5. Edit the elements you want by placing your cursor in the element and entering or deleting data.
  6. Save the record when you finish making changes.
See also:
Viewing Files in Data Exchange