4 Authority for deductions. Whether and to what extent deductions shall be allowed

depends upon specific legislative acts, and only where there is a clear provision can any particular deduction be allowed. Therefore, a deduction will be allowed only if the taxpayer can establish the validity and correctness of such deduction. This rule is intended to implement Iowa Code sections 422.7 and 422.9. [Editorial change: IAC Supplement 11/2/22]