The Art and Architecture Thesaurus The AAT is a structured vocabulary containing around 125,000 terms and other information about concepts. Terms in AAT may be used to describe art, architecture, decorative arts, material culture, and archival materials. The coverage of the AAT ranges from Antiquity to the present, and the scope is global. The J. Paul Getty Trust The J. Paul Getty Trust Copyright © 2000 The J. Paul Getty Trust. All rights reserved. Government Category List Version 2.1 The GCL (Government Category List) is a structured list of categories for use with the Subject.category element of the e-GMS. 2004-07-01 UK GovTalk The GCL is updated twice a year.