If the taxpayer departs from or modifies the method of valuing property or of excluding property from or including property in the property factor used in returns for prior years, the taxpayer shall disclose in its Arkansas return for the current year the nature and extent of the modification.
If the returns filed by the taxpayer with all states to which the taxpayer reports are not uniform in the valuation of property or in the exclusion or inclusion of property in the property factor, the taxpayer shall disclose in its Arkansas return the nature and extent of the variance.
2.26 Ark. Code R. 51-710