Basic MARC Terms: Subfields, Delimiters and Subfield Codes

Subfields: Most of the fields in a MARC record contain several pieces of information. Each of these pieces is important, and often in a library catalog these pieces of information need to be searchable. Each of these pieces is called a Subfield and there are various ways to set these apart and to let the computer know where specific pieces of information can be found. Some of the possible subfields in the 245 field mentioned are title, subtitle, statement of responsibility, and format (also called medium).

In this example of the 245 field, there are two subfields: the title The school library media manager, and the author "Blanche Woolls".

Delimiters: This is a character or symbol that is used in front of each subfield in the MARC record. The delimiter indicates to the computer that a different piece of information is coming. There are several different characters that are used as delimiters, but the most common ones are $, ≠, or _.

In this example, as in all of the examples in this course, the delimiter seen is ‘$’. Here it occurs before the title and again before the author’s name.

Subfield Codes: This is an alphabetical indicator that specifies the type of information in each Subfield shown in a MARC record. Depending on the style of the MARC display, the Subfield Code will be listed immediately after each delimiter or the Subfield Codes will be grouped together after the five digits of the tag and indicators. Subfield Codes are similar to Indicators, because the same letter may mean different things in different fields. It is very important in MARC records that the Subfield Codes are correctly specified. For the example above, ≠a indicates the title, ≠b indicates the subtitle, ≠c indicates the statement of responsibility, and ≠h indicates the format, or medium.

In this example, two subfield codes occur, matching the two subfields indicated above. In the 245 field, the subfield code ‘a’ indicates the title, and the subfield code ‘c’ indicates the statement of responsibility

Here are two more examples from complete MARC records, showing just the 245 field that has been used as an illustration above:

245 00$aLibrary evaluation :$ba casebook and can-do guide /$cDanny P. Wallace, Connie Van Fleet, editors.

245 00$aWorld Book millennium 2000$h[computer file].

As you can see from these examples, the integrity of the AACR2 cataloging guidelines is preserved in the MARC record format. Delimiters are inserted when needed, but the punctuation and style of the AACR2 rules is still intact in the MARC record.

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