Proprietary file format

File format that is not a free and open format

A proprietary file format is a file format of a company, organization, or individual that contains data that is ordered and stored according to a particular encoding-scheme, designed by the company or organization to be secret, such that the decoding and interpretation of this stored data is easily accomplished only with particular software or hardware that the company itself has developed. The specification of the data encoding format is not released, or underlies non-disclosure agreements. A proprietary format can also be a file format whose encoding is in fact published, but is restricted through licences such that only the company itself or licensees may use it. In contrast, a open or free format is a file format that is published and free to be used by everybody.

This keyword could refer to multiple things. Here are some suggestions: