proprietary protocol

In telecommunications, a proprietary protocol is a communications protocol owned by a single organization or individual

Ownership by a single organization gives the owner the ability to place restrictions on the use of the protocol and to change the protocol unilaterally. Specifications for proprietary protocols may or may not be published, and implementations are not freely distributed. Proprietors may enforce restrictions through control of the intellectual property rights, through enforcement of patent rights, and by keeping the protocol specification a trade secret