# R-VAL: Validation Rules
## Validation Rules
Validation is the act of a credentialed third party signing that data meets a specific standard. These rules prevent conflicts of interest and ensure regulatory-grade assurance.
`R-VAL-01` **Accredited Validators Only**
Only principals holding a valid `cth:ValidatorCredential` may sign validation results. Validator credentials list the specific methodologies and standards the holder is accredited to validate.
**Implementation:** OPA `validate.rego` checks credential claims. Unsigned or self-signed validation results are rejected at ingestion.
`R-VAL-02` **No Self-Certification**
A Data Submitter may not validate their own submission. The validator DID must differ from the submitter DID. This applies transitively — a validator who is a beneficial owner of the submitting entity is also disqualified.
**Implementation:** Ledger constraint: `submission.submitter_did ≠ validation.validator_did`. Beneficial ownership conflicts flagged via off-chain KYC check at validator onboarding.
`R-VAL-03` **CBAM and Article 6 Require Validation**
EUDR DDS can be self-declared by the operator (EU Regulation 2023/1115 Article 4). However, CBAM declarations (Article 7) and Article 6.4 carbon credits require third-party validation before a Digital Conformity Credential (DCC) can be issued.
**Implementation:** Compliance export endpoint checks `validation_status` field. CBAM and Art.6 exports blocked if no signed DCC present.