Libraries are grouped into four major types: public, school, academic, and special. The U.S. Geological Survey's (USGS) National Wetlands Research Center (NWRC) library is classified as a special library because it is sponsored by the Federal government, and the collections focus on a specific subject. The NWRC library is the only USGS library dedicated to wetland science. Library personnel offer expert research services to meet the informational needs of NWRC scientists, managers, and support personnel. The NWRC library participates in international cataloging and resource sharing, which allows libraries from throughout the world to borrow from its collections. This sharing facilitates the research of other governmental agencies, universities, and those interested in the study of wetlands.