AI Search Optimization (ASO) is the practice of engineering how AI systems retrieve, validate, and cite information about a brand so it appears accurately in AI-generated answers. It focuses on three layers: retrieval (being found in model browsing/RAG), trust (being verifiable as the correct entity), and citation (being easy and safe to quote). In practice, ASO is implemented through canonical entity identity, validator-clean entity-linked JSON-LD, knowledge graph alignment, and answer-first content designed for quoting.