persistent format

n. an encoding format used to preserve digital data because it is expected to remain usable, reliable, and accessible over a long period of time  


Persistent formats are defined by a number of characteristics that help ensure the formats’ suitability for the preservation of digital information. First among these is the quality of being open; this means the format is not proprietary (controlled by the corporation that created it), and that the documentation of the format is free and open to everyone. Another characteristic is ubiquity; a format that is commonly used (such as PDF/A, which is a subset of PDF) is much more likely to endure than one that is open but used by a small number of people. Sometimes, persistence is defined by its being long-lived; a format that has existed for decades (such as ASCII) has proved its durability and, thus, its suitability for preservation. Other characteristics of persistent formats include the ability to reproduce data accurately, to support robust metadata, and to resist deterioration over time. Persistent formats, for instance, would not employ lossy data compression algorithms, which could lead to incremental data loss.