000: Main Category

100: Popular Starting Points
150: Other General Sites
*200: Specialized Sites 
300: Indexes and Directories
400: Government Agencies
450: Government Publications
*500: Basic Government Publications 
*600: Specialized Government Publications 
*700: Reference 
740: Research Centers and Other Educational Sites
780: Interest Groups and Other Political Organizations
790: Reports
800: Statistics
*810: Statistics by Subject
950: Other Sites
975: Print Sources
451: United Nations
456: European Union
461: Other European International Org.
476: Other International Org.
Additional Sites: 
*Subcategory: