A gift made by one spouse to any person other than his spouse shall, for the purposes of this chapter, be considered as made one-half by him and one-half by his spouse, but only if at the time of the gift each spouse is a citizen or resident of the United States. This paragraph shall not apply with respect to a gift by a spouse of an interest in property if he creates in his spouse a general power of appointment, as defined in section 2514(c), over such interest. For purposes of this section, an individual shall be considered as the spouse of another individual only if he is married to such individual at the time of the gift and does not remarry during the remainder of the calendar year.
Paragraph (1) shall apply only if both spouses have signified (under the regulations provided for in subsection (b)) their consent to the application of paragraph (1) in the case of all such gifts made during the calendar year by either while married to the other.
A consent under this section shall be signified in such manner as is provided under regulations prescribed by the Secretary.