Final answer:
The number '162' in the citation Reg. §1.162-2(a)(1) stands for the related Code section, specifically Section 162 of the Internal Revenue Code.
Step-by-step explanation:
In the citation Reg. §1.162-2(a)(1), the number '162' stands for the related Code section. The citation refers to a specific section in the Internal Revenue Code (IRC) that provides guidance on the deductibility of trade or business expenses. The '162' in the citation refers to Section 162 of the IRC, which covers ordinary and necessary business expenses.