1 USC 1 - Words denoting number, gender, and so forth

In determining the meaning of any Act of Congress, unless the context indicates otherwise words importing the singular include and apply to several persons, parties, or things; words importing the plural include the singular; words importing the masculine gender include the feminine as well; words used in the present tense include the future as well as the present; the words insane and insane person and lunatic shall include every idiot, lunatic, insane person, and person non compos mentis; the words person and whoever include corporations, companies, associations, firms, partnerships, societies, and joint stock companies, as well as individuals; officer includes any person authorized by law to perform the duties of the office; signature or subscription includes a mark when the person making the same intended it as such; oath includes affirmation, and sworn includes affirmed; writing includes printing and typewriting and reproductions of visual symbols by photographing, multigraphing, mimeographing, manifolding, or otherwise.