General Material Designation (GMD) is a phrase or term interposed in brackets following the title of a catalogue or archive record to denote an item's material type.
Examples of GMD terms commonly used in institutional cataloguing to identify material types include: cartographic material, electronic resource, game, graphic, kit, manuscript, microform, motion picture, music, realia, sound recording, and video recording.
[1] Other GMD terms, such as braille, microfilm, and motion picture are used to eliminate different cataloging practices which were previously used by libraries.
Despite being superseded by the Resource Description and Access (RDA) rules, the GMD is still used in many institutions.
In recent years, a number of issues regarding GMD have arisen, including lack of terms to define new material types, lack of consistency in application by different library systems, incompatibility with needs of special libraries and museums, and the difficulty of relating to digital forms.