<div> The emergence of Large Language Models as primary knowledge interfaces has fundamentally altered how entities are discovered, understood, and referenced. Traditional visibility strategies, designed for search engine environments, assume that ranking in a list of results defines success. This assumption no longer holds in AI-mediated discovery contexts. </div> <div> <br> </div> <div> This document introduces Perception Control as a foundational category for navigating this new environment. Perception Control is not a refinement of optimization. It is a categorically different approach: managing how AI systems interpret entities rather than how search engines rank pages. </div> <div> <br> </div> <div> This whitepaper defines the category, explains why it is distinct from SEO and GEO, and clarifies what Perception Control is and what it is not. </div>