Displays are sections of text to be set off from the body of the paper. Major quotes, tables, and figures are types of displays, as are all the examples used in this document.
Major quotes are quotes that are several lines long, and hence are set in from the rest of the text without quote marks around them.
A list is an indented, single-spaced, unfilled display. Lists should be used when the material to be printed should not be filled and justified like normal text, such as columns of figures or the examples used in this paper.
A keep is a display of lines that are kept on a single page if possible. An example for a keep might be a diagram. Keeps differ from lists in that lists may be broken over a page boundary whereas keeps are not.
Floating keeps move relative to the text. Hence, they are good for things that are referred to by name, such as “See figure 3”. A floating keep appears at the bottom of the current page if it fits; otherwise, it appears at the top of the next page. Meanwhile, the surrounding text ‘flows’ around the keep, thus leaving no blank areas.