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Thesaurus for Graphic Materials I (TGM): An Introduction

I.E. MARC Coding

TGM I is one of several standard thesauri authorized for use in the 650 field of MARC records. TGM I terms are entered in the subfield $a of the 650 field. The Library of Congress has assigned the code "lctgm" to this thesaurus. The source of each term is made apparent by the field indicator 7 and subfield $2 code, which are required elements.

Example:  650 -7 $a [TGM I term]. $2 lctgm

          650 -7 $a Cheerleading. $2 lctgm

Subdivisions are entered in other subfields in the 650 field: general (topical and nationality) subdivisions are entered in subfield $x; geographic subdivisions are entered in subfield $z; chronological subdivisions are entered in subfield $y.

Example:  650 -7 $a Soldiers $x Italian $y 1940-1950. $2 lctgm
          Soldiers--Italian--1940-1950. lctgm

Example:  650 -7 $a Schools $z Illinois $z Chicago $y 1890-1900. $2 lctgm
          Schools--Illinois--Chicago--1890-1900. lctgm

(For further information on subdivisions, see Section III.)