an open file format or open format is a file format for storing digital data, defined by a openly published specification usually maintained by a standards organization, and which can be used and implemented by anyone. open file format spesification is licensed with open license. for example, an open format can be implemented by both proprietary and open-source software. in contrast to open file formats, closed file formats are considered trade secrets. however, the actual image used by an open file format may still be copyrighted or trademarked.