This document presents a structural taxonomy of describability based on carrier-free closure, stabilization under refinement, and a strict separation between representation, projection, and regime activation. It provides a unified architectural framework for understanding when and how stable descriptions arise across physics, mathematics, and other disciplines, and for identifying principled limits of describability. Physics is treated as a particular stabilized descriptive region rather than a foundational ontology, while mathematical fields are classified as families of admissible projections. Mixed descriptive regions and out-of-plateaux domains, where stabilization fails, are explicitly incorporated. The document represents the current conceptual culmination of a body of prior technical work by the author, which is not cited here in order to preserve structural focus. It is intended as a reference framework for revising and constraining specialized theories (including finite-resolution physics, stabilized symmetry models, and closure-based gravity), and as a foundation for further technical developments.