NGDA Theme CommunitiesAn A-16 NGDA Theme is defined within OMB Circular A-16 and Supplemental Guidance as representations of conceptual topics describing digital spatial information for the Nation. Themes contain associated datasets (with attribute records and coordinates) that are documented, verifiable, and officially designated to meet recognized standards. A theme contains one or more datasets of geographic information to be used in common and from which other datasets can be derived. Themes are originally described in OMB Circular A-16 Appendix E – NGDA Data Themes, Definitions, and Lead Agencies.
Updates to Appendix E can be found here.
Current Theme definitions can be found here.