All questions relating to the application and interpretation of wage
determinations (including the classifications therein) issued pursuant
to part 1 of this subtitle, of the rules contained in this part and in
parts 1 and 3, and of the labor standards provisions of any of the
statutes listed in Sec. 5.1 shall be referred to the Administrator for
appropriate ruling or interpretation. The rulings and interpretations
shall be authoritative and those under the Davis-Bacon Act may be relied
upon as provided for in section 10 of the Portal-to-Portal Act of 1947
(29 U.S.C. 259). Requests for such rulings and interpretations should be
addressed to the Administrator, Wage and Hour Division, Employment
Standards Administration, U.S. Department of Labor, Washington, DC
20210.