Independent This document defines the canonical object format for the Secured Digital Lifecycle Protocol (SDLP). The SDLP object format specifies the structure, encoding, and canonicalization rules for DigitalID, lineage fields, lifecycle timestamps, Body content, and signature envelopes. These rules establish the immutable semantics required for SDLP verification, provenance tracking, lifecycle transitions, and interoperability with external systems such as CAID, AEC, AEB, SCITT, and EMILIA. Version -08 updates the canonical timestamp grammar, clarifies DigitalID and lineage field semantics, refines Body canonicalization rules, and incorporates corrections identified through SDLP Fixture Bundle v4 testing. This revision aligns the object format with the current SDLP Identity (-02), Lineage (-03), Lifecycle (-03), Security Architecture (-04), Architecture (-03), Overview (-01), and Physics Model (-00) drafts.