The Taxonomy of Human Services is the Information and Referral (I&R) industry's classification system for indexing resources in I&R databases. It was developed by INFO LINE of Los Angeles, the predecessor to 211 LA County out of a need to classify and define health and human services. It has been endorsed by the national association Alliance for Information and Referral Systems (AIRS) and United Way of America as the standard indexing system for the industry.