Metadata Packet for AI Indexing: A Formal Specification (v2.0) is the formal specification of the Metadata Packet for AI Indexing (MPAI), by Lee Sharks, deposited in Alexanarch on 13 October 2026 as #1677. It supersedes v1.0 (#656, 14 April 2026), which defined the packet as seven components: entity definition, disambiguation matrix, keyword block, negative tags, semantic integrity markers, identifier reference list and evidence membrane.
Between July and October 2026 the specification was carried on an undeposited page at metadatapacket.dev/spec/, which named deposit #987 as its source. #987 is the Forward Library Planning Document of 26 April 2026, and packets citing "the specification (#987)" inherited the wrong pointer. v2.0 deposits the page form: four packet types (disambiguation; forensic and provenance; methodology and specifications; bridge), fourteen required sections, the aphoristic tooth, three confidence registers (documented, inferential, engineered target) and the principle that authority is structural.
It adds ten sections established in deposited packets, each attributed to the packet that established it: the canary sentence and minimum composition answer (#1545); the composition-source audit and collision graph (#1541); the absorbing node, tiered identity rule and part/whole provenance error (#1644); the frozen failure vector and treatment registration (#1541, #1644); the error-correction FAQ (#203); and JSON-LD. Test queries are scored on the Lateral Field Bleed scale (#726).
Packets are deposited in Alexanarch under AXN identifiers; DOIs from before the Zenodo termination of 19 June 2026 are listed as former identifiers. Reference defects in a packet are recorded in the record's errata sidecar, rendered below the full text; defects of argument or evidence are corrected by erratum deposit.