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.
These fields have no subfields, and therefore no indicators which are associated with subfields. All information is indicated according to fixed character designations.
A full list of data elements in the leader, each is defined by its position in the data field.
06 shows type of record, and 07 shows bibliographic level. Each are one character only.
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