Certification is the L2 verification primitive in the Rosie architecture: the institutional authority's warrant that an artifact meets the standards the institution is responsible for upholding.

Certification differs from attestation in two structurally important ways:

1. Institutional, not personal. An attestation carries a single expert's name and reputation; a certification carries an institution's standing. When a trade association certifies a compliance interpretation, the association — not the certifying signatory as an individual — is on the hook for the warrant. The signatory's role is to confirm that the institution's standards have been met; the standing behind the warrant belongs to the institution.
2. Authoritative, not advisory. A certification is what members, regulators, and external parties treat as the institution's official position. Other forms of review (peer comment, advisory opinion, working-paper feedback) may inform the certification, but they don't carry the institution's authority by themselves. Certification is the line at which institutional commitment begins.

The certifying authority's substantive role: standing behind the artifact against future challenge. When a customs ruling is later disputed, when a tariff classification is audited, when a regulatory interpretation is tested in litigation — the certifying institution defends the artifact as its own work product. This is why "certification" is a heavier word than "approval," "endorsement," or "review." It commits the institution.

For trade associations specifically: certification is what their authority actually warrants. The substantive value an association provides — the thing that distinguishes it from a peer-review service or a member-discussion forum — is precisely its institutional standing to certify. The platform exists to make that certification structurally addressable: not just "the association says this is right," but "this specific artifact, citing these specific attestations, certified on this date, under this version of the institution's standards, persists as a permanent verifiable record."

Worked example: an industry trade association certifies a compliance interpretation in its domain. The interpretation cites three L1 attestations (regulatory classification, methodology, supporting documentation), each from a domain specialist. The trade association's certification accepts those attestations as sufficient and adds the association's institutional warrant: the interpretation is now what the trade association stands behind. A challenge to the interpretation is, structurally, a challenge to the trade association.