An issue that overburdens the tax-exempt bond market (within the meaning of paragraph (a)(4) of this section) is subject to the following special limitations --
(i) Special yield restriction.
Investments are subject to the definition of materially higher yield under section 1.148-2(d) that is equal to one-thousandth of 1 percent. In addition, each investment is treated as a separate class of investments under section 1.148-5(b)(2)(ii), the yield on which may not be blended with that of other investments.
(ii) Certain regulatory provisions inapplicable.
The provisions of section 1.148-5(c) (relating to yield reduction payments) and section 1.148-5(e)(2) and (3) (relating to recovery of qualified administrative costs) do not apply.
(iii) Restrictive expenditure rule.
Proceeds are not allocated to expenditures unless the proceeds-spent-last rule under section 1.148-6(d)(3)(i) is satisfied, applied by treating those proceeds as proceeds to be used for restricted working capital expenditures. For this purpose, available amount includes a reasonable working capital reserve as defined in section 1.148-6(d)(3)(iii)(B).