MARC 21 Format - Overview

MARC 21 Format:

The MARC 21 formats are widely used standards for the representation and exchange of data in machine-readable form.  The data output from DOCLINE in MARC 21 format is holdings data with some bibliographic data originally from NLM's online public access catalog, LocatorPlus.  Data output in MARC 21 format can be used by libraries that have the ability to import such data into a system that reads MARC 21 format.
Data Output:
For a Single Library:  Sort based upon the Bibliographic Sort Serial Name.  The holdings record appears first followed by the bibliographic record.
Special Characters:
Blank:  ASCII character 20(hex)
Field Terminator (FT):  ASCII control character 1E(hex) is used to terminate the Directory and each variable field within a record.
Record Terminator (RT):  ASCII control character 1D(hex) is used to terminate a record.  It follows the field terminator of the last data field.
Fill Character:  Hex "7C" - designated at | in the Holdings Data and the Bibliographic Data.
Additional resources: