to a retirement bond, except as determined by the Secretary. (C) Regulations The Secretary may issue such regulations as are necessary to carry out the purposes of this section, including— (i) establishment of procedures to communicate to individuals the importance of investment diversification and the transfer option described in clause (ii), (ii) simplified procedures under which holders of retirement bonds may periodically choose to have the bonds or their proceeds transferred to available Roth IRAs, and (iii) means by which individuals may elect (or be treated as electing) whether to have retirement bonds or their proceeds so transferred. Any such transfer shall be treated as a rollover contribution for purposes of section 408(d)(3) (other than subparagraph (B) thereof). (f) Other definitions and special rules (1) Modified adjusted gross income For purposes of this section, the term modified adjusted gross income means adjusted gross income— (A) determined without regard to sections 911, 931, and 933, and (B) determined without regard to any exclusion or deduction allowed for any qualified retirement savings contribution made during the taxable year. (2) Treatment of contributions In the case of any contribution under subsection (a)(2)— (A) except as otherwise provided in this section or by the Secretary under regulations, such contribution shall be treated in the same manner as a contribution made by the individual on whose behalf such contribution was made, (B) such contribution shall not be treated as income to the taxpayer, and (C) such contribution shall not be taken into account with respect to any applicable limitation under sections 402(g)(1), 403(b), 408(a)(1), 408(b)(2)(B), 408A(c)(2), 414(v)(2), 415(c), or 457(b)(2). (3) Treatment of qualified plans, etc A plan or arrangement to which a contribution is made under this section shall not be treated as violating any requirement under section 401, 403, 408, or 457 solely by reason of accepting such contribution. (4) Erroneous credits If any