This topic describes some basic cataloguing terms.
MARC (MAchine-Readable Cataloguing) is a format standard for the storage and exchange of bibliographic records and related information in machine-readable form. All MARC Standards conform to: ISO 2709:1996 Information and documentation -- Format for Information Exchange.
For specific MARC 21 rules view: http://www.loc.gov/marc/
Each bibliographic record is divided logically into fields. There is a field for the author, a field for title information, and so on. These fields are subdivided into one or more "subfields."
The textual names of the fields are too lengthy to be reproduced within each MARC record, so instead they are represented by 3-digit tags. (Although online catalogues may display the names of the fields, the names are supplied by the system software, not by the MARC record.)
Each field is associated with a 3-digit number called a "tag." A tag identifies the field — i.e. the kind of data — that follows. Even though a printout or screen display may show the tag immediately followed by indicators (making it appear to be a 4- or 5-digit number), the tag is always the first 3 digits.
The tags used most frequently are:
010 marks the Library of Congress Control Number (LCCN) 020 marks the International Standard Book Number (ISBN) 100 marks a personal name main entry (author) 245 marks the title information (which includes the title, other title information, and the statement of responsibility) 250 marks the edition 260 marks the publication information 300 marks the physical description (often referred to as the "collation" when describing books) 490 marks the series statement 520 marks the annotation or summary note 650 marks a topical subject heading 700 marks a personal name added entry (joint author, editor, or illustrator)
In the MARC record, 10% of the tags are used over and over and the other 90% are seen only rarely. After even a short exposure to the MARC 21 format, it is not unusual to hear librarians speaking in "MARCese." Librarians who work with MARC records soon memorize the numbers for the fields common to the materials they catalogue.
Subfields are marked by subfield codes and delimiters.
Most fields contain several related pieces of data. Each type of data within the field is called a subfield, and each subfield is preceded by a subfield code. Fields 001 through 009 have no subfields.
For example, the field for a book's physical description (defined by the tag 300) includes a subfield for the extent (number of pages), a subfield for other physical details (illustration information), and a subfield for dimensions (centimeters). For example:
300 ## $a 675 p. : $b ill. ; $c 24 cm.
Subfield codes are one lowercase letter (occasionally a number) preceded by a delimiter. A delimiter is a character used to separate subfields. Each subfield code indicates what type of data follows it. (For each field in the MARC 21 bibliographic format, the MARC 21 documentation lists and describes the valid subfield codes.)
Different software programs use different characters to represent the delimiter on the screen or on printouts. Examples are a double dagger, an at sign "@", a dollar sign "$", an underline "_" or the graphic symbol "ǂ". In the help we've used the dollar sign ($) is used as the delimiter portion of the subfield code.
In the example for the 300 field above, the subfield codes are $a for the extent, $b for other physical details and $c for dimensions.
Two character positions follow each tag (with the exception of Fields 001 through 009). One or both of these character positions may be used for indicators.
In some fields only the first or second position is used, in some fields both positions are used, and in some fields — e.g. the 020 and 300 fields — neither is used. When an indicator position is not used, that indicator is referred to as "undefined" and the position is left blank. It is the convention to represent a blank, or undefined, indicator position by the character "#".
Each indicator value is a number from 0 to 9. (Although the rules say it can be a letter, letters are uncommon.) Even though two indicators together may look like a 2-digit number, they really are two single-digit numbers. The allowable indicator values and their meanings are spelled out in the MARC 21 documentation. In the example below, the first 3 digits are the tag (245 defines this as a title field) and the next 2 digits (a 1 and a 4) are indicator values. The 1 is the first indicator, the 4 is the second indicator.
245 14 $a The emperor's new clothes / $c adapted from Hans Christian Andersen and
illustrated by Janet Stevens.
A first indicator value of 1 in the title field indicates that there should be a separate title entry in the catalogue. In the card catalogue environment, this means that a title card should be printed for this item and an entry for "Title" added to the tracings. A first indicator value of 0 would mean that a title main entry is involved; the card would be printed with the traditional hanging indention, and no additional tracing for the title would be required (since it is the main entry).
One of the more interesting indicators is the second indicator for the title field. It displays the number of characters at the beginning of the field (including spaces) to be disregarded by the computer in the sorting and filing process. For the title "The emperor's new clothes", the second indicator is set to "4" so that the first four characters (the "T", the "h", the "e" and the space) will be skipped and the title will be filed under "emperor's."
Copying a bibliographic record into a new bibliographic record.
Creating a new bibliographic record.
Loading a file of MARC records into Spydus.