An ellipsis is an omission of material, usually of words in a quotation, but also to show a pause or trailing off of thought. It is indicated by three dots, known as ellipsis points. If the ellipsis points appear at the end of a sentence, the final punctuation mark, usually a period, is retained: Shakespeare’s most quoted passage may be Hamlet’s soliloquy, which begins, “To be, or not to be. . . .”