OCL spec v0.1 (draft)

1. Roles and principles

• Rater: rates an item and signs its label. Identified by an internet host name (for example rate.shinifrontiers.com) that publishes its public keys.
• Creator: attaches the signed label to the item.
• Checker: anyone (browser, platform, parent app, regulator) who reads a label and checks it.
• A valid signature proves who rated an item, not that the rating is right. Which raters count is for the regulator to list, not for any rater.
• Ratings are advisory opinions. A label is never a certification, a guarantee or legal advice.
• Labels hold no personal data. Checking a label needs no tracking script and sends nothing about the viewer to the rater.
• Labelling never changes the item: no re-encoding, watermarking or editing.

2. The label

A label is a JSON object (UTF-8). All fields below are required in v0.1.

Age band on local scales

Influence categories

fun, education, inspiration (what the content gives) and fight, threat_fear, sexual, substances, risky_stunts, commercial_push, political, body_pressure, hate (what it pushes).

Example

{
  "label_id": "754fe7cfd476531e0b95fb6c",
  "spec_version": "0.1",
  "item_type": "website",
  "subject": "example.com",
  "rater": "rate.shinifrontiers.com",
  "age_band": "teen",
  "age_band_scales": {"india": "13+", "eu_kids_act": "13-14", "pegi": "12"},
  "influence": {"fun": 2, "education": 1, "inspiration": 0, "fight": 0, "threat_fear": 0,
                "sexual": 0, "substances": 0, "risky_stunts": 1, "commercial_push": 1,
                "political": 0, "body_pressure": 0, "hate": 0},
  "flags": ["imitation_risk"],
  "confidence": "medium",
  "method": "ocl-website-0.1",
  "rated_at": "2026-10-31T09:00:00+00:00",
  "expires_on": "2027-01-29",
  "signature": "eyJhbGciOiJFZERTQSIsImtpZCI6Im9jbC1yYXRlci0xIn0..<signature>"
}

3. Signing

1. Canonical form: the label without its signature field, serialised as JSON with keys sorted, no spaces (separators , and :), UTF-8, non-ASCII characters left as they are.
2. Header: {"alg":"EdDSA","kid":"<key id>"}.
3. Signing input: base64url(header) + "." + base64url(canonical form) (base64url without padding).
4. Signature: Ed25519 (pure EdDSA, RFC 8032) over the signing input.
5. Detached form in the label: "signature": "<header>..<signature>" (empty middle part), so the label stays readable JSON.
6. Compact token for pages: <header>.<canonical payload>.<signature>, a standard JWS that carries the whole label.

Rater keys

Each rater publishes its public keys as a JWK set at https://<rater>/.well-known/ocl-keys.json, readable from any origin:

{"keys": [{"kty": "OKP", "crv": "Ed25519", "kid": "ocl-rater-1", "x": "<public key, base64url>", "use": "sig"}]}

Only public parts are published. A rater keeps a retired key in this file until every label signed with it has expired. Our keys: /.well-known/ocl-keys.json; our signing key is held in a hardware-backed key service and cannot be exported.

4. Attaching a label to a website

A website publishes either or both of these. The file is preferred.

File: /.well-known/ocl.json

{
  "ocl": "0.1",
  "site": "https://example.com",
  "labels": [{
    "paths": ["/*"],
    "label": "https://rate.shinifrontiers.com/label/754fe7cfd476531e0b95fb6c",
    "rater": "rate.shinifrontiers.com",
    "signed_label": { ...the signed label... }
  }]
}

Tags in the <head> of each page

<link rel="ocl-label" href="https://rate.shinifrontiers.com/label/754fe7cfd476531e0b95fb6c">
<meta name="ocl" content="<compact token>">

In v0.1 one label covers the whole site (paths: ["/*"]). Per-path labels, apps (manifest entry and store listing), video (C2PA assertion, metadata added by stream copy) and chatbots (OCL-Label response header) are planned for later versions and described in the explainer; they are not final in v0.1.

5. Checking a label

1. Find the label: https://<host>/.well-known/ocl.json, else the start page's <meta name="ocl"> with its <link rel="ocl-label">. Neither present: the site is unrated.
2. Rater: the entry's rater, or the host of the ocl-label link.
3. Keys: fetch https://<rater>/.well-known/ocl-keys.json over HTTPS and pick the key whose kid matches the signature header.
4. Signature: verify as in section 3. The label's own rater field must equal that rater (www. ignored).
5. Binding: the label's subject must equal the site checked (www. ignored), so a label copied to another site fails.
6. Expiry: today must be on or before expires_on.

The label is valid only if all checks pass. Whether to trust the rater is then the checker's (or regulator's) decision. Proposed default for platforms: content with no valid label is treated as unrated and hidden from child accounts.

Reference checker: our label check page, and its open API GET https://rate.shinifrontiers.com/verify?site=example.com (JSON). It checks labels from any rater.

6. Changes

• v0.1 (31 Oct 2026): first public draft. Adds the required rater field inside the signed label, so a label names who signed it.

Comments and proposals: contact@shinifrontiers.com. This specification may be implemented by anyone without charge.