An introduction to the classification principles for documents at the Non-Formal Education Information Center is given for the cataloger. The classification scheme, itemized in the first section, consists of 11 main categories such as concepts, training methods, program content, bibliographies, and countries. The next section details classification and coding procedures. The author/organization index file is then explained, with special attention given to international organizations, in-country agencies, and acronyms. The subject index file contains cross-reference cards for documents with multiple subjects. Two other small index files--the organizations arranged-by-subject file and the projects and programs file--allow the searcher to locate quickly documents referring to specific organizations or projects. Finally, the steps in preparing and filing index file cards are enumerated. (SW)