評稅基期 - 古德明

問：最近學習稅務原則，讀到利得稅（profits tax）的評稅基期（basis period）規例："Basis period" refers to the period on the income / profits of which tax for that year of assessment ultimately falls to be computed。這一句結構複雜，先生可不可以分析一下？
答：這一句的確非常複雜難解，而我對稅務條例理解非常有限，多方參閱basis period的解釋之後，才或算明白。假如解釋有誤，盼熟悉稅務條例的讀者賜正。
按原句的which，當然是指起句的basis period。這評稅基期和課稅年度（year of assessment）未必相同。比如說，某公司的會計年度（accounting year）是七月初到六月杪，而當地的課稅年度是四月初到三月杪，那麼，該公司的評稅基期應是七月初到三月杪。沒有這個理解，我實在讀不懂讀者示下那一句。而根據這個理解，那一句可用兩個方式改寫，從中讀者當可看到原句結構：（1）"Basis period" refers to the accounting period which falls in the relevant year of assessment, on the profits / income from which tax is assessed。（2）"Basis period" refers to the accounting period which falls in the relevant year of assessment. Tax on the profits / income from this "basis period" is computed for that assessment year。
原句是典型的官僚英語（bureaucratese），絕對不是簡潔易懂的好英文，也絕對不值得仿效。