Standardization of On-Chain Identity Publication

Dear bitcoin-dev, I am submitting a draft Bitcoin Improvement Proposal titled *“Standardization of On-Chain Identity Publication”* for discussion. The draft specifies canonical CBOR payloads, Poseidon-based `nullifier_hash` domain separation (`v0iden` / `v0corp`), and an optional Ed25519 signature wrapper. The proposal text and implementation notes are available in this PR: https://github.com/bitcoin/bips/pull/2038 . I welcome review and feedback on interoperability, canonicalization (deterministic CBOR), and security considerations.