Physics and Astronomy Classification Scheme (PACS)

Physics and Astronomy Classification Scheme (PACS)- A subject-specific, hierarchical classification scheme prepared by the American Institute of Physics (AIP) in collaboration with certain other members of the International Council on Scientific and Technical Information (ICSTI). The site provides the 1996, 1998, and 1999 versions, browsable on-line, or downloadable in PDF, text, or WordPerfect format.