1  –  ALL_ROLES

    Revokes all roles assigned to the users listed.

2  –  FROM

 Syntax options:

    FROM username | FROM role-name | FROM PUBLIC

    Specifies the user, role, or the PUBLIC user from which the
    specified role is to be revoked.

3  –  role-name

    The name of an existing role created with the CREATE ROLE
    statement or created automatically by the GRANT statement.