Latin words and phrases are useful in formal writing but consider whether the English equivalent is less pretentious. They should be set in italics or underlined and correctly punctuated.
cf. confer (= compare) used especially with references e.g. exempli gratia (= for example) (≠ i.e.) et al. et alia (= and others) see Citations and References etc. et cetera (= and so on) ib. or ibid. ibidem (= in the same book, paper or chapter) id. idem (= by the same author) i.e. id est (= that is) (≠ e.g.) i.q. idem quod (= the same as) opt. cit. opere citato (= in the work quoted) q.v. quod vide (= which see) used when citing a reference sensu (= as meant or used by) used when citing a reference (sic) in a quotation this shows that errors are transcribed as in the original viz or viz. videlicet (= namely) None may be singular or plural depending on the context.