In the administration of this chapter the recorder shall interpret its provisions consistently with those Documentary Stamp Tax Regulations adopted by the Internal Revenue Service of the United States Treasury Department which 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, which regulations are attached hereto and incorporated by reference herein as if set forth fully herein, except that for the purpose of this chapter, the determination of what constitutes “realty” shall be determined by the definition or scope of that term under state law. (Prior gen. code § 2-31.06)