Structured data standard for machine-readable entity markup. Implement using JSON-LD in website
. Minimum viable: Organization/Person type, name, url, sameAs, description, contactPoint. Advanced: DefinedTermSet for vocabulary, HowTo for methodologies, Course for training. Validate using Google Rich Results Test and Schema Markup Validator. Inconsistent schema across pages causes entity confidence degradation. Required for KGMID assignment and OG-RAG compatibility. Update quarterly to maintain temporal consistency.