(1) Unused electromagnetic spectrum between TV channels. Originally set up as protection bands to eliminate interference, wireless microphones used in theaters and other venues have employed this spectrum. See White Spaces Coalition.

(2) Any area on a document page that does not contain text or graphics. Also called "negative space," the term was derived from printing paper, which was typically white, and any part of the paper not printed remained white. To a graphic designer whose goal is to render a pleasing result, white space is as important as the printed areas.

(3) Non-printing characters. Applications treat white space differently. For example, in word processing, each depression of the space bar generates one blank space character (ASCII 32), and each blank space character is displayed as one blank space (rather logical).

On Web pages (HTML pages), multiple, contiguous space characters are treated as a single character of white space (not so logical). In order to actually display several blank spaces in a row, a non-breaking HTML code must be used instead of multiple space characters.

(4) A void in service; for example, white spaces in the cellular industry are geographic areas without coverage.