Institutions should formulate written policies for assigning terms in their own systems. For example, users can choose, based on their institutions, whether to assign only broad terms such as POSTERS or use more specific terms such as CIRCUS POSTERS. Automated or manual system considerations as well as indexing practices would guide this decision. Bibliographic networks may provide members with many necessary guidelines. Conformance to established book cataloging and indexing conventions is recommended for pictorial material; however, in some circumstances a departure from usual practice is justified. The guidelines here reflect practices developed and ongoing in the Library of Congress Prints and Photographs Division and may be helpful for other pictorial collections having manual files or MARC and non-MARC automated files.
TGM II is part of a set of tools developed specifically to address various aspects of picture cataloging. Others are: the descriptive cataloging manual Graphic Materials: Rules for Describing Original Items and Historical Collections, which supplements the Anglo-American Cataloguing Rules (2nd ed. revised); the Thesaurus for Graphic Materials I: Subject Terms (companion to this thesaurus), which provides an extensive list of topical subject headings to be used in MARC field 650.