00-02 - Tag
03-06 - Field length
07-11 - Starting character position
Series of fixed length entries, with one entry for each variable field (control or data) present in a separate holdings record. Each Directory entry is 12 character positions in length and contains three portions: the field tag, the field length, and the starting character position. The Directory immediately follows the Leader at the beginning of the record and is located at character position 24. The Field length and Starting character position portions of the Directory are defined by Leader/20-23 (Entry map) as being 4 and 5 characters in length, respectively. Because a field tag is always 3 characters, the length of the Tag portion of the Directory is not specified in the Entry map.
More detailed information about the structure of the Directory entries is contained in the MARC 21 Specifications for Record Structure, Character Sets, and Exchange Media.
|Tag||Field length||Starting character position|
Library of Congress >> MARC >> Holdings >> Directory(03/08/2008)