In the administration of the provisions of this chapter, the County Clerk-Recorder shall interpret its provisions consistently with the Documentary Stamp Tax Regulations adopted by the Internal Revenue Service of the Treasury Department of the United States, which regulations relate to the tax on conveyances and identified as Sections 47.4361-1, 47.4361-2, and 47.4362-1 of Part 47 of Title 26 of the Code of Federal Regulations, as the same existed on November 8, 1967; provided, however, for the purposes of this chapter, the determination of what constitutes “realty” shall be determined by the definition or scope of such term under State law. (§ 14, Ord. 578, as renumbered by § 5, Ord. 590)