The secretary of revenue shall adopt, by rule promulgated pursuant to chapter 1-26, a standard real estate appraisal manual for all urban and rural property which shall be used by all directors of equalization in the state in complying with the provisions of chapter 10-6. The secretary shall also establish, by rule, the information and the procedures to be used in the cost, market and income approaches to valuation.
SDCL 10-1-16.1