In the exchange of information over a communications channel, an out-of-band agreement is 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.
By extension, in a client–server or provider-requester setting, an out-of-band agreement is an agreement or understanding that governs the semantics of the request/response interface but which is not part of the formal or contractual description of the interface specification itself.
Famous quotes containing the word agreement:
“A marriage based on full confidence, based on complete and unqualified frankness on both sides; they are not keeping anything back; there’s no deception underneath it all. If I might so put it, it’s an agreement for the mutual forgiveness of sin.”
—Henrik Ibsen (1828–1906)