2000 Edition
Table of Contents
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 provides 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.
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 2907. 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
- Data elements that provide information for the processing of the record.
The data elements contain numbers or coded values and are identified by relative
character position. The Leader is fixed in length at 24 character positions
and is the first field in all MARC record.
-
- Directory
- 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 (hex 1E).
-
- 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 (hex 1D). There are two types of
variable fields:
-
- Variable control fields
- The 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 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 (hex 20), represented
in this document as a #, 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 $, 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.
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 in each format.
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.
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.
A display constant is a term, phrase, and/or spacing or punctuation convention that may
be system generated in order 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.
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. 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 $a (Original cataloging 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 are not included in this document. A Web listing
is available under MARC Field Lists at: //www.loc.gov/marc/marcdocz.html.
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.
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 (hex 1F)
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) and the
lowercase roman-alphabet letter l (eye) (hex 6C) in examples or text.
- |
- The graphic | represents a fill character (hex
7C).
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.
| AACR 2 |
Anglo-American Cataloguing Rules, 2nd edition, and
2nd edition (1988 revision); and AACR 2 based cataloging manuals |
| ANSI |
American National Standards Institute |
| DDC |
Dewey Decimal Classification |
| ISBD |
International Standard Bibliographic Description |
| ISBN |
International Standard Book Number formulated according to
Book numbering (ANSI/NISO Z39.21) |
| ISO |
International Organization for Standardization |
| ISRC |
International Standard Recording Code |
| ISSN |
International Standard Serial Number formulated according
to International Standard Serial Numbering (ANSI/NISO Z39.9) |
| LCC |
Library of Congress Classification |
| LCSH |
Library of Congress Subject Headings |
| MeSH |
Medical Subject Headings |
| NISO |
National Information Standards Organization |
| NR |
Not repeatable |
| R |
Repeatable |
| STRN |
Standard Technical Report Number (STRN), Format and Creation
(ANSI/NISO Z39.23) |
The MARC 21 Concise Formats is prepared by the Network Development and
MARC Standards Office. This electronic concise format is organized into parts
that generally mirror the tabbed sections of the full printed format documentation.
Each part is divided into chapters that usually cover a single field and all
of the data elements possible within it (that is, character positions for fixed-length
fields and indicators and subfield codes for variable length fields). In each
format, the Leader and the Directory are described in the first main part, followed
by parts containing the variable control fields and variable data fields arranged
in numerical field tag order.
Obsolete and deleted content designators are not listed. They are found the
full printed version of the format and in the electronic MARC field lists.
The following list gives the MARC 21 format documents whose data elements have been
incorporated into this edition of the
MARC 21 Concise Formats:
-
MARC 21 Format for Authority Data (1999 base text), and
Update No. 1 (October 2000)
-
MARC 21 Format for Bibliographic Data (1999 base text), and
Update No. 1 (October 2000)
-
MARC 21 Format for Classification Data (2000 base text), and
Update No. 1 (October 2000).
-
MARC 21 Format for Community Information (2000 base text),
and Update No. 1 (October 2000).
-
MARC 21 Format for Holdings Data (2000 base text), and
Update No. 1 (October 2000).
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