tokenTypeHint

OPTIONAL. A hint about the type of the token submitted for introspection. The protected resource MAY pass this parameter to help the authorization server optimize the token lookup. If the server is unable to locate the token using the given hint, it MUST extend its search across all of its supported token types. An authorization server MAY ignore this parameter, particularly if it is able to detect the token type automatically. Values for this field are defined in the "OAuth Token Type Hints" registry defined in OAuth Token Revocation (RFC7009).