Except as otherwise provided, amounts are allocable to only one issue at a time as gross proceeds, and if amounts simultaneously are proceeds of one issue and replacement proceeds of another issue, those amounts are allocable to the issue of which they are proceeds. Amounts cease to be allocated to an issue as proceeds only when those amounts are allocated to an expenditure for a governmental purpose, are allocated to transferred proceeds of another issue, or cease to be allocated to that issue at retirement of the issue or under the universal cap of paragraph (b)(2) of this section. Amounts cease to be allocated to an issue as replacement proceeds only when those amounts are allocated to an expenditure for a governmental purpose, are no longer used in a manner that causes those amounts to be replacement proceeds of that issue, or cease to be allocated to that issue because of the retirement of the issue or the application of the universal cap under paragraph (b)(2) of this section. Amounts that cease to be allocated to an issue as gross proceeds are eligible for allocation to another issue. Under section 1.148-10(a), however, the rules in this paragraph (b)(1) do not apply in certain cases involving abusive arbitrage devices.