subfield code

n.DescriptionA delimiter followed by a data element identifier to mark the beginning of different types of information within a field.


For example, in the MARC format field 245, Title and statement of responsibility, subfield code a indicates the title proper; subfield code b, other title information; and subfield c, the statement of responsibility. Because the delimiter is a nondisplaying control character (ASCII 31), different systems use different characters to display it. The dollar sign ($) or pipe (|) is often used to represent the delimiter. For example, $aAlice in Wonderland / $cLewis Carroll.


USMARC 1994, p. 7 Subfield codes identify the individual data elements within the field, and precede the data elements they identify. Each data fields contains at least one subfield code. The subfield code consists of a delimiter [1F16, 8-bit] followed by a data element identifier. Data element identifiers defined in USMARC may be any ASCII lowercase alphabetic or numeric character. In general, numeric identifiers are defined for data used to process the field, or coded data needed to interpret the field. Alphabetic identifiers are defined for the separate elements which constitute the data content of the field.