Not to be confused with Out of bounds in programming languages; See Bounds checking.
The present disambiguation page holds the title of a primary topic, and an article needs to be written about it. It is believed to qualify as a broad-concept article. It may be written directly at this page, or drafted elsewhere then moved over here. Related titles should be described in Out-of-band, while unrelated titles should be moved to Out-of-band (disambiguation).
Out-of-band is activity outside a defined telecommunications frequency band, or, metaphorically, outside some other kind of activity.
Out-of-band agreement, an agreement or understanding between the communicating parties that is not included in any message sent over the channel but which is relevant for the interpretation of such messages