A – Agriculture

C3- Census Bureau (Commerce Department)

D – Defense Department

E – Energy Department

ED – Education Department

GA – General Accounting Office

GS – General Services Administration

HE – Health and Human Services Department

I – Interior Department

I 19. – U.S. Geological Survey (Interior Department)

J – Justice Department

JU – Judiciary

L – Labor Department

LC – Library of Congress

NAS – National Aeronautics and Space Administration

PrEx – Executive Office of the President

S – State Department

SI – Smithsonian Institution

TD – Transportation Department

X,Y – Congress