SPXI (Semantic Packet for eXchange & Indexing): A Formal Specification — EA-SPXI-01

SPXI (Semantic Packet for eXchange & Indexing) — pronounced "spexy" — is a protocol specification for the durable inscription of entities into AI-mediated knowledge systems. Unlike SEO (page-level optimization) and GEO (content-level extraction optimization), SPXI constructs entity-definition objects at the structured reference layer through DOI-anchored deposits on institutional infrastructure. This document specifies the components, structure, and deployment protocol of an SPXI packet: entity definition blocks, disambiguation matrices, semantic integrity markers (SIMs), DOI reference lists, retrieval instructions, and JSON-LD encoding. It includes the five-step deployment protocol (audit → assemble → deposit…