Identifying forms and formats via MARC fields

The Library of Congress MARC data represent bibliographic and related information in machine-readable form. Extracting data from Marc records helps to identify and categorize materials, and create groups such as books, videos, serials, physical vs. electronic, etc. MARC records are detailed and contain all possible information about the material such as author, title, language, date of publication, etc.

Information is stored as ‘fields’. Each field contains a particular type of information. Many fields contain subfields, and each subfield is identified by an 'indicator' or an alphanumeric code to specify what type of information is contained in the subfield. For example, NEED EXAMPLE.

For general queries, we usually need to extract data from a few fields only. These fields are described below. The rest of the fields include record length, coding scheme, etc., which are usually not of interest in materials-related queries. 

FIXED FIELDS

                These fields have no subfields, and therefore no indicators which are associated with subfields. All information is indicated according to fixed character designations (example with code below), 

The leader field (000)

The 000 field can contain upto eight data elements, where each is defined by its position in the data field. The two main elements of interest are 06 (type of record), and 07 (bibliographic level). Each is only one character.

06 - Type of record

a - Language material

c - Notated music

d - Manuscript notated music

e - Cartographic material

f - Manuscript cartographic material

g - Projected medium

i - Nonmusical sound recording

j - Musical sound recording

k - Two-dimensional nonprojectable graphic

m - Computer file

o - Kit

p - Mixed materials

r - Three-dimensional artifact or naturally occurring object

t - Manuscript language material

07 - Bibliographic level

a - Monographic component part

b - Serial component part

c - Collection

d – Subunit

i - Integrating resource

m - Monograph/Item

s – Serial

NOTE: We need to select the correct value in the column labeled 'field', because the 'content' column contains values for all the data elements of the selected field.

It is important to note that the ‘content’ field in the table begins with a 0, which is not included in the character count. So the 7^th space indicates the 06 character, and the 8^th space is for the 07 character.  

The code above specifies that we are starting at the 7th space in the contents column, and we are selecting two spaces: the 7^th and the 8^th. 

In the screenshot of the marc table below, the 7^th and 8^th characters are highlighted in the ‘content’ field. The ‘a’ in the 7^th space shows that the resource is language material (from the 06 character) and the ‘m’ in the 8^th space shows that the resource is a monograph/item (from the 07 character).

Example code to extract information from the 06 and 07 data from the marc table in Metadb:

SELECT instance_id, field, substring(sm."content", 7, 2) AS "format_code"

FROM folio_source_record.marc__t AS sm

WHERE field ='000';

The results table below show that rows 1 and 2 are monographs (07=m) which are non-musical sound recordings (06=i). (In library terms, a monograph refers to any non-serial publication including but not limited to books, reports, and audio-visual materials.) The remaining rows can be classified in a smilar manner using the 06 and 07 charcters of tyhe 000 leader field.

Other Control Fields - 00X (001, 003, 005, 006, 007, 008)

These fields also have no indicators or subfield codes. The first three are not often relevant for query writers.

NOTE: Information is somewhat randomly contained in the numeric order of the fields. For example, field 006 contains information that cannot fit into 008. 

Fixed Field 008 - Bibliographic Details

The 008 field contains information about the physical form of the resource, such as form of material, language, etc. Some characters are common for all materials, and others differ based on material. For example, characters 7-10 and 11-14 indicate date1 and date2 respectively, for all materials. However, characters 8-21 indicate type of illustration for books, and characters 18-19 indicate form of composition for music. 

There are seven possible material configurations: Books (BK), Computer Files (CF), Maps (MP), Music (MU), Continuing Resources (CR), Visual Materials (VM), and Mixed Materials (MX).  Once  the material type has been determind by the system from the leader field, we can obtain information relevant to that specific material type from the 008 field.

It is important to know that material configurations in the 008 field are determined by the system and not by the cataloger, depending on cataloger entries for the 000 leader field. 

A record is determined to be a book if it meets the following criteria in the 000 leader field: (character 6 = a or t) AND (char 7  = a, c, d, or m). If this takes place, then in the 008 field, a record is created using the BK definition. In no place does it say ‘BK’. That’s not a possible code. See this documentation for details. Once the cataloger enters the requisite configuration in the leader 000 field, when they go to the 008 field, they will receive options only for possible book details (see screen shot below from the Cataloger's Reference Shelf documentation). 

Example: the screenshot below contains