The Human Relations Area Files (HRAF) are a compilation, indexing, and distribution of a collection of ethnographic and other texts that are indexed by culture and subject, from 400 member institutions located in over 30 nations. HRAF indexes the information in its collection of ethnography by culture and subject. OWC is an acronym for the Outline of World Cultures, a systematic listing of the cultures of the world; an OWC code, or OWC number, is a culture identification code. The OWC number is a four character alpha-numeric id derived from the classification scheme presented in the Outline of World Cultures. Each distinct culture in the list of Cultures Covered in eHRAF is assigned an OWC number and text on that culture has been indexed using that OWC. OCM stands for "Outline of Cultural Materials", a thesaurus-like listing of subject descriptors used to index the texts included in the eHRAF Collections. An OCM code, or OCM number, is a three-digit numeric code for a subject descriptor that is decribed in the Outline of Cultural Materials. The OCM lists approximately eighty broad terms and over seven hundred narrower terms that are used to index the texts at the paragraph level. Both the OWC and OCM lists are browsable in the Web version of HRAF.
