(a) For rules relating to the refund or credit of income tax withheld under chapter 3 of the Code on nonresident aliens and foreign corporations and tax-free covenant bonds, see Sec. 1.6414-1 of this chapter (Income Tax Regulations).
(b) For rules relating to the refund or credit of income tax withheld under chapter 24 of the Code from wages, see Sec. 31.6414-1 of this chapter (Employment Tax Regulations).