(1) In filing returns with this state, if the taxpayer departs from or modifies the basis for excluding or including gross receipts in the sales factor used in returns for prior years, the taxpayer shall disclose in the return for the current year the nature and extent of the modification.

(2) If the returns or reports filed by the taxpayer with all states to which the taxpayer reports under Article IV of the Multistate Tax Compact or the Uniform Division of Income for Tax Purposes Act are not uniform in the inclusion or exclusion of gross receipts, the taxpayer shall disclose in its return to this state the nature and extent of the variance.