A CXU is an atomic knowledge unit containing a claim, supporting quotes, and metadata, and it uses a content-addressable ID based on `1220` plus SHA-256 so that each unit is self-contained and uniquely addressable.

**CXU (Context Unit):** Atomic knowledge unit with claim, supporting quotes, and metadata; content-addressable ID (1220 + SHA-256)

— PYRANA_PLATFORM_ARCHITECTURE_REFERENCE.md

Atomic knowledge unit

— PYRANA_PLATFORM_ARCHITECTURE_REFERENCE.md

claim, supporting quotes, and metadata

— PYRANA_PLATFORM_ARCHITECTURE_REFERENCE.md