AUTHORITY: section 142.621, RSMo 1986. Regulations 2–4 were filed July 17, 1972, effective July 27, 1972. Amended: Filed Nov. 9, 1983, effective March 11, 1984. Amended: Filed Sept. 8, 1989, effective Jan. 26, 1990. Rescinded: Filed Jan. 26, 2018, effective July 30, 2018. Consolidated Freightways Corp. of Delaware v. State, 503 SW2d 1 (Mo. banc 1972) cert. denied 412 U.S. 919. The Department of Revenue’s interpretation of the 1965 Motor Vehicle Fuel Tax Act as applying to special fuels as well as motor fuels should be given serious consideration by the courts in construing the intent of the Act, as a rule of statutory construction. However, this rule of statutory construction is applied only to statutes or constitutional provisions which are ambiguous or uncertain. We do not find the 1965 Act to be reasonably susceptible to different constructions; thus there is no ambiguity and no occasion to apply the rule of administrative interpretation.