Community participation through tagging, ratings, and reviews in the Encore discovery system allows patrons to provide contextual information and insights that help others discover materials. Tagging requires patron authentication but no staff mediation, and tags can be closely managed if desired. The new Encore 3.0 release includes a simple 5-star rating system and ability to write brief reviews, with patron authentication required. These social features are popular with patrons and administrators and are integrated into the Encore discovery interface.