Under section 10 of the Portal-to-Portal Act of 1947 (29 U.S.C. 259), official interpretation issued under the Fair Labor Standards Act of 1938 may, under certain circumstances, be controlling in determining the rights and liabilities of employers and employees. The interpretations of the law contained in this part are official interpretations on which reliance may be placed as provided in section l0 of the Portal-to-Portal Act so long as they remain effective and are not modified, rescinded, or determined by judicial authority to be incorrect. However, the failure to discuss a particular problem in this part or in the interpretations supplementing it should not be taken to indicate the adoption of any position by the Secretary of Labor or the Administrator with respect to such problem or to constitute an administrative interpretation or practice or enforcement policy.