The following 2 OAuth Access Token Type values were found in all available specifications. Please be advised that the table shown here is maintained and compiled from Web Concepts sources. The official OAuth Access Token Type registry is maintained by the Internet Assigned Numbers Authority (IANA).

OAuth Access Token Type Specification
Bearer RFC 6750: The OAuth 2.0 Authorization Framework: Bearer Token Usage
mac Internet Draft ietf-oauth-v2-http-mac: OAuth 2.0 Message Authentication Code (MAC) Tokens