All I want for this Christmass is an authoritative list of all US federal agencies. I kid you not, there is no such list and the number of federal agencies is uncertain. From Wikipedia:
>Legislative definitions of a federal agency are varied, and even contradictory, and the official United States Government Manual offers no definition. While the Administrative Procedure Act definition of "agency" applies to most executive branch agencies, Congress may define an agency however it chooses in enabling legislation, and subsequent litigation, often involving the Freedom of Information Act and the Government in the Sunshine Act. These further cloud attempts to enumerate a list of agencies.