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 → distribute → verify) and the distinction table separating SPXI from SEO and GEO. GEO makes your content more digestible. SPXI makes your entity irreducible. Hex: 06.SEI.SPXI.01 | Domain: spxi.dev | Institute: Semantic Economy Institute Disambiguation: SPXI as defined in this document is unrelated to the BetaPro S&P 500 Daily Inverse ETF (TSX: SPXI). SPXI Self-Audit Block embedded. Material available on condition of non-erasure.