Introduction
MARC stands for Machine-Readable Cataloging. It is a standard format developed to allow bibliographic information to be read and interpreted by computers. MARC records are used globally by libraries to share, store, and manage cataloging data electronically. The current and most widely used version is MARC 21.
What is a MARC Record?
A MARC record is a digital format for the description of an item in a library catalog, such as a book, map, film, or electronic resource. It includes various pieces of information like title, author, publisher, subject, and classification data, all coded in a specific structure readable by library software systems.
In simple terms, a MARC record is like a digital version of a catalogue card, formatted so that computers can understand and process it efficiently.
Structure of a MARC 21 Record
The MARC 21 format has a specific structure consisting of three main parts:
1. Leader
The Leader is the first 24 characters of every MARC record. It gives information about the record itself, such as:
- Type of record (e.g., bibliographic, authority)
- Record length
- Encoding level (e.g., full or abbreviated)
- Bibliographic level (e.g., monograph or serial)
2. Directory
The Directory lists all the data fields in the record and tells where each field starts and how long it is. Each entry is 12 characters long and corresponds to a field in the record.
3. Variable Fields
This is the main body of the MARC record and contains the actual cataloguing data. It has two types of fields:
- Control Fields (001–009): These are fixed fields that contain standard control information.
Example: Field 008 holds coded information such as publication date, language, etc. - Data Fields (010–999): These are variable fields with bibliographic details. Each field includes:
- Tag: 3-digit number indicating the field (e.g., 100 for author)
- Indicators: Two characters giving more info about the field
- Subfields: Smaller parts of the field, each with a code and data
Common MARC 21 Fields with Examples
- 100: Main Entry – Personal Name (e.g., Author)
- 245: Title Statement (e.g., Title and subtitle)
- 250: Edition Statement
- 260 or 264: Publication Info (Place, Publisher, Date)
- 300: Physical Description
- 650: Subject Headings
- 700: Added Entry – Other Contributors
Advantages of MARC 21
- Allows consistent cataloguing across libraries
- Enables data sharing and union catalog creation
- Machine-readable, ideal for automation and library software
- Supports international cataloguing standards
Conclusion
MARC 21 plays a central role in modern library management. It provides a structured and standardized format for bibliographic data that can be shared and processed by computers. By using MARC records, libraries around the world maintain efficient, searchable, and connected catalog systems.