The Central Bank of the Republic of China (Taiwan) Act Article 43

The gain or loss from the Bank's assets or liabilities denominated in gold, silver, foreign currencies and other forms of international reserve, resulted from changes in parity of the national currency, or changes in the value, parity or exchange rate of these assets and liabilities relative to the national currency, shall not be listed in the Bank's annual income stateatement.Any gain from the above changes shall be posted in the Exchange Reserve Account, and any loss shall be offset in the balance of that Account.
中文原文 中央銀行法第43條
本行以黃金、白銀、外幣及其他國際準備計算之資產或負債,如其價值因國幣平價之改變,或此類資產、負債對國幣之價值、平價或匯率改變而發生利得或損失,均不得列為本行年度損益。
前項變動所生之利得,應列入兌換準備帳戶;其損失應由兌換準備帳戶餘額抵沖。

English translation for reference only; the Chinese text prevails. Not legal advice.