A MARC holdings record consists of three main components:  the Leader, the Directory, and the variable fields.  For additional information, see Components of a MARC Record.  More detail is provided in MARC 21 Specifications for Record Structure, Character Sets, and Exchange Media.

Within the 853-878 holdings data fields, certain parallels of content designation are preserved.  The following meanings are given to the final character of the tag in these fields:


Basic Bibliographic Unit


Supplementary Material



In these fields, the same subfield codes are defined for the caption and enumeration and chronology, and item information data elements.

See also:

Holdings Data Format:  Introduction