#link https://review.opendev.org/q/topic:bp%252Foauth2-client-credentials-ext
#link https://review.opendev.org/q/topic:bp%252Fenhance-oauth2-interoperability
External OAuth 2.0 Specification
#link https://review.opendev.org/c/openstack/keystone-specs/+/861554 (merged)
OAuth 2.0 Implementation
#link https://review.opendev.org/q/topic:bp%252Fsupport-oauth2-mtls
OAuth 2.0 Documentation
#link https://review.opendev.org/c/openstack/keystone/+/838108 (merged)
#link https://review.opendev.org/c/openstack/keystoneauth/+/838104 (merged)