offline_access

Why Tier 3

It reaches no permission on the reference, so it gets the lowest tier.

Asks for an expiring token with a refresh token. Grants nothing by itself.

GitHub: Requests an expiring access token and a refresh token, even if your OAuth app is not configured to use expiring tokens. Use this scope to test and gradually roll out support for expiring tokens. For more information, see Authorizing OAuth apps.