CAS Source Index

The CAS Source Index (CSI) is a comprehensive database maintained by the U.S. Library of Congress that uniquely identifies and catalogs publishers of legal materials, including court cases, statutes, and regulations. It assigns a unique number to each publisher, helping libraries, legal professionals, and researchers accurately track, organize, and access legal documents from various sources. Essentially, CSI acts as a standardized directory, ensuring consistent identification of legal publishers and improving the efficiency of legal research and information management.