Ellipsis points are series of dots that indicate an omission, or ellipsis, in a quotation. A reader asks when to use three dots and when to use four, and where the period goes in relation to the ellipsis points.

The ellipsis itself consists of three periods. If the omission occurs within a sentence, use three periods, with a space on either side:

"This ellipsis business is a . . . pain."

"Give me your . . . huddled masses yearning to be free."