MARC 21 Bibliographic Format

2004 Concise Edition

Authority Format published online on February 9, 2005
Bibliographic Format published online on February 9, 2005
Community Information Format published online on February 9, 2005

Classification Format published online on February 9, 2005
Holdings Format published online on February 9, 2005

Table of Contents


GENERAL INTRODUCTION

The MARC 21 Concise Formats are officially published online once a year (usually in October through December). It uses red highlights to indicate changes made from the previous published edition.

The MARC 21 formats are widely used standards for the representation and exchange of authority, bibliographic, classification, community information, and holdings data in machine-readable form. They consist of a family of five coordinated formats: MARC 21 Format for Authority Data; MARC 21 Format for Bibliographic Data; MARC 21 Format for Classification Data; MARC 21 Format for Community Information; and MARC 21 Format for Holdings Data. Each of these MARC formats is published separately to provide detailed field descriptions, guidelines for applying the defined content designation (with examples), and identification of conventions to be used to insure input consistency. The MARC 21 Concise Formats provide in a single publication a quick reference guide to the content designators defined in each MARC format. It provides a concise description of each field, each character position of the fixed-length data element fields, and of the defined indicators in the variable data fields. Descriptions of subfield codes and coded values are given only when their names may not be sufficiently descriptive. Examples are included for each field.

COMPONENTS OF A MARC 21 RECORD

MARC format characteristics that are common to all of the formats are described in this general introduction. Information specific only to certain record types is given in the introduction to the MARC format to which it relates.

A MARC record is composed of three elements: the record structure, the content designation, and the data content of the record. The record structure is an implementation of the American National Standard for Information Interchange (ANSI/NISO Z39.2) and its ISO equivalent ISO 2709. The content designation--the tags, codes, and conventions established explicitly to identify and further characterize the data elements within a record and to support the manipulation of that data are defined by each of the MARC formats. The content of the data elements that comprise a MARC record is usually defined by standards outside the formats, such as the International Standard Bibliographic Description (ISBD), Anglo-American Cataloguing Rules, 2nd edition (AACR 2), Library of Congress Subject Headings (LCSH), Holdings Statements Summary Level (ISO 10324), American National Standard for Serial Holdings Statements (ANSI/NISO Z39.44), Library of Congress Classification (LCC), or other conventions used by the organization that creates a record. The content of certain coded data elements (e.g., the Leader, fields 007 and 008) is defined in the MARC formats themselves.

The MARC record structure consists of three main components: the Leader, the Directory, and the Variable Fields. The following information summarizes the components of a MARC record. More detail is provided in MARC 21 Specifications for Record Structure, Character Sets, and Exchange Media.

Leader
Contains data elements that provide information for the processing of the record. The data elements contain numbers or coded values and are identified by a relative character position. The Leader is fixed in length at 24 character positions and is the first field in all MARC records.

Directory
Contains a series of entries that contain the tag, length, and starting location of each variable field within a record. Each entry is 12 character positions in length. Directory entries for variable control fields appear first, sequenced by tag in increasing numerical order. Entries for variable data fields follow, arranged in ascending order according to the first character of the tag. The stored sequence of the variable data fields in a record does not necessarily correspond to the order of the corresponding Directory entries. Duplicate tags are distinguished only by the location of the respective fields within the record. The Directory ends with a field terminator character (ASCII 1E hex).

Variable fields
The data in a MARC 21 record is organized into variable fields, each identified by a three-character numeric tag that is stored in the Directory entry for the field. Each field ends with a field terminator character. The MARC record ends with a record terminator (ASCII 1D hex). There are two types of variable fields:

Variable control fields
The tagged 00X fields. The variable control fields are structurally different from the variable data fields. These fields contain neither indicator positions nor subfield codes. They may contain either a single data element or a series of fixed-length data elements identified by relative character position.

Variable data fields
The tagged 01X-8XX fields.

Within variable data fields, the following two kinds of content designation are used:

Indicator positions
The first two character positions at the beginning of each variable data field that contain values which interpret or supplement the data found in the field. Indicator values are interpreted independently, that is, meaning is not ascribed to the two indicators taken together. Indicator values may be a lowercase alphabetic or numeric character. A blank (ASCII 20 hex), represented in this document as a pound symbol (#), is used in an undefined indicator position. In a defined indicator position, a blank may be assigned a meaning, or may mean no information provided.

Subfield codes
Two characters that precede each data element within a field that requires separate manipulation. A subfield code consists of a delimiter (hex 1F), represented in this document as a dollar sign ($), followed by a data element identifier. Data element identifiers are lowercase alphabetic or numeric characters. Subfield codes are defined independently for each field; however, parallel meanings are preserved where possible. Subfield codes are defined for purposes of identification. The order of subfields is generally specified by standards for the data content, such as the cataloging rules.

MULTISCRIPT RECORDS

A MARC 21 record may contain data in multiple scripts. One script may be considered the primary script of the data content of the record, even though other scripts are also used for data content. (Note: ASCII is used for the structure elements of the record, with most coded data also specified within the ASCII range of characters.) Graphic models for multiscript data are described in the "Multiscript Records" sections, located at the end of each format.

FIELD AND SUBFIELD REPEATABILITY

Theoretically, all fields and subfields may be repeated. The nature of the data, however, often precludes repetition. For example, a record may contain only one 1XX field; a bibliographic field 100 may contain only one subfield $a (Personal name) but may contain more than one subfield $c (Titles and other words associated with a name). Field and subfield repeatability/nonrepeatability is indicated by (R) or (NR) following each field and subfield in each MARC 21 format.

FILL CHARACTER AND RELATED VALUES

A fill character (ASCII 7C hex), represented in this document as a vertical bar (|), may be used in a record when the format specifies a code to be used but the creator of the record decides not to attempt to supply a code. A fill character may not be used in any character position of the leader or tags, indicators, or subfield codes. The use of the fill character in records contributed to a national database may also be dependent upon the national level requirements specified for each data element.

Code u (Unknown or unspecified), when it is defined, is used to indicate that the creator of the record attempted to supply a code but was unable to determine what the appropriate code should be.

Code n (Not applicable), when it is defined, is used to indicate that the characteristic defined by the position is not applicable to a specific type of item or kind of record.

DISPLAY CONSTANTS

A display constant is a term, phrase, and/or spacing or punctuation convention that may be system generated to make a visual presentation of data in a record more meaningful to a user. The display text is not carried in the record but an indication for it, based on tags, indicators, subfield codes, or coded values, is. Suggested display constants and display examples are provided in each MARC 21 format. The use and display of these constants is determined by each organization or system.

Record Content Responsibility

In general, the responsibility for the data content, content designation, and transcription of data within a MARC 21 record may be determined by examination of the field indicated in the responsible parties section below. The data content of certain data elements, however, is restricted when the element is an agency-assigned or an authoritative-agency data element.

Responsible Parties

In unmodified records, the organization identified as the original cataloging source in 008/39 and/or 040 $c (Transcribing agency) is responsible for the data content of the record. The organizations identified as the transcribing agency in field 040 is responsible for the content designation and transcription of the data.

In modified records, organizations identified in field 040 $a (Original cataloging agency) and $d (Modifying agency) are collectively responsible for the data content of the record. Organizations identified as transcribing or modifying agencies in field 040 $c and $d are collectively responsible for the content designation and transcription of the data.

Agency-Assigned Data Elements

An agency-assigned data element is one whose content is determined by a designated agency and is the responsibility of that agency, e.g., field 222 (Key Title) which is the responsibility of an ISSN Center. While it is usually input by the designated agency, it may be transcribed by another organization.

Controlled-List Data Elements

Certain data elements contain data from controlled lists maintained by designated agencies, e.g., the MARC Code List for Geographic Areas in field 043 (Geographic Area Code) of the bibliographic format.

These elements are indicated at the field or subfield level in MARC 21 and only values from the designated lists may be used. If a change or addition is desirable for a list, the maintenance agency for the list should be consulted.

OBSOLETE CONTENT DESIGNATORS

Obsolete content designators are not included in this document. A Web listing is available under the MARC Field Lists at: www.loc.gov/marc/. An obsolete content designator is not used in new records. It may appear in records that were created prior to the time that it was made obsolete.

TYPOGRAPHICAL CONVENTIONS

Throughout this document, the following typographical conventions are used:

0 - The graphic 0 represents the digit zero in tags, fixed-position character position citations, and indicator positions. This character is distinct from an uppercase letter O used in examples or text.

# - The graphic symbol # is used for a blank (hex 20) in coded fields and in other special situations where the existence of the character blank might be ambiguous.

$ - The graphic symbol $ is used for the delimiter (ASCII 1F hex) portion of a subfield code. Within the text, subfield codes are referred to as subfield $a, for example.

/ - Specific character positions of fixed-length data elements, such as those in the Leader, Directory, and field 008, are expressed using a slash and the number of the character position, e.g., Leader/06.

1 - The graphic 1 represents the digit one (hex 31). This character must be distinguished from a lowercase roman alphabet letter l (el) (hex 6C) and the uppercase alphabetic letter I (eye) (hex 49) in examples or text.

| - The graphic | represents a fill character (hex 7C).

ACRONYMS AND INITIALISMS

The acronyms and initialisms that are used in the MARC 21 Concise Formats are only briefly defined here. Detailed explanations may be found in the relevant documentation named in the brief definition, the MARC 21 Specifications for Record Structure, Character Sets, and Exchange Media, and/or one of the five MARC 21 communications format publications.

DOCUMENTATION MAINTENANCE

The MARC 21 Concise Formats are prepared by the Network Development and MARC Standards Office. Direct any questions related to the content of this document to the Library of Congress, Network Development and MARC Standards Office, 101 Independence Ave., S.E., Washington, DC 20540-4402 (FAX +1-202-707-0115). Correspondence may also be sent to the office email account at: ndmso@loc.gov.

The following list gives the MARC 21 format documents whose data elements have been incorporated into this edition of the MARC 21 Concise Formats :

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