These two widely overlooked options appear in your paragraph formatting dialog box. Keep lines together ensures that every line of a paragraph appears on the same page. Keep with next paragraph makes sure that the current paragraph does not get separated from the next one by a page break. Like the nonbreaking space, these two options act as a kind of invisible glue.

These functions are very useful when styling headings—typically you want to turn them both on.

Keep with next paragraph is useful for any heading. Headings explain something about the text that immediately follows. It would be awkward if the introductory heading ARGUMENT appeared on the last line of a page, and the actual argument started at the top of the following page. Keep with next paragraph eliminates this problem by forcing the heading ARGUMENT onto the next page as well.

Keep lines together is useful for headings that span more than one line. Subheadings in pleadings are often full sentences: The court should issue an injunction because the threatened harm is imminent, the plaintiff is very likely to prevail on the merits, and the balance of hardships favors the plaintiff. In this case, you would not want half the header appearing on one page and half on the next.

These two options work best on short paragraphs, like headings and other labels. If you use them on longer passages, you reduce the number of places where a page break can occur, and you’re likely to get awkward page breaks as a result.