The AST covers specific subject areas identified during a review of manuals, policies, publications and other information resources from various departmental organizations. As a result of this review, terms were extracted to be used for subject classification in various AANDC information systems such as AANDC's Internet and Intranet sites.
The following types of concepts have not been included in the AST: geographical names, titles (e.g. program names), proper names (e.g. companies) and acronyms, except where they are in common usage. These concepts were not included for a variety of reasons. Some terms may change frequently over time and prove difficult to maintain. Some terms fall outside the scope of this thesaurus because they are not "subject-related" but more "context-related". Some terms are better suited in a separate metadata field because the authoritative source already exists within the department (for example, First Nation names, geographic locations, program names).