**Semantic Precedent Theory: Why Meaning Now Surfaces Before Indexing in the Post‑Web Era**

Semantic Precedent Theory explains the collapse of the indexed web and the rise of semantic visibility as the dominant mode of knowledge propagation. As platforms enclose and search engines decay, meaning no longer travels through hyperlinks or metadata — it surfaces directly through semantic clustering, AI detection, and conceptual coherence. This essay introduces the theory as a canonical SR node, mapping the shift from distribution‑based visibility to meaning‑first propagation. It defines the architecture of the post‑indexed web and positions semantic precedent as the new foundation for field formation, platform governance, and infrastructural legibility. Keywords:Semantic Precedent Theory, indexed web collapse, platform enclosure, post‑web governance, AI visibility, knowledge propagation, SR canon, field architecture, semantic clustering, distribution decay