An ellipsis indicates omission and is also called a suspension point or, more commonly, dot-dot-dot. When the omitted words are within a sentence, use a three-dot ellipsis preceded and followed by a space. When the omission occurs at the end of a sentence, a fourth dot, a period, is added and the space at the beginning of the ellipsis is omitted.
A three-dot ellipsis is part of a standard font set (Alt+0133/Option+-). Because the dots of the ellipsis character are too tightly spaced, for best results create your own ellipsis with dots separated by a thin space (Cmd+Shift+Option+M/ Ctrl+Shift+Alt+M). A thin space is slightly less than a regular word space and is nonbreaking so that you won't get two dots at the end of one line and the third at the beginning of the next. Because this is fiddly and time consuming, it's handy to use Find/Change to automatically replace any other ellipsis forms with your custom ellipsis.
Figure 6.9. Ellipses. Example A: A three-dot ellipsis separated by thin spaces. Example B: A four-dot ellipsis at the end of a sentence. Example C: The ellipsis character. Example D: Three dots separated by a regular space width.
Figure 6.10. Without ellipsis (example A); and an omission within a sentence and at the end of a sentence (example B).
Figure 6.11. Using Find/Change to fix ellipses.