Instructions concerning the abatement and the refunding of taxes and penalties which are uncollectible, abatable, or refundable under the provisions of sections 3220 and 3221, revised statutes, section 6, act of March 1, 1879 or other acts, and the redemption of or allowance for internal-revenue stamps under the provisions of the act of May 12, 1900, as amended by the act of June 30, 1902