A sustainable digital format is one that is compatible, for the foreseeable future, with software needed to open and read it.
In order to read most types of digital data, you need to open it in a compatible software. Unfortunately, as software applications change or disappear over time, data file formats can become obsolete. If there is a risk of your data format becoming obsolete during its useful lifetime, you may need to migrate it to a new format. The resources needed to do this could be included as a budget item in your data plan.
Wherever possible, select data formats that have the following sustainability attributes:
|Adheres to specifications that are publically documented (versus formats based on proprietary specifications).||TIFF (Tagged Image File Format) format for images.|
|Is in widespread use and readable with available software.||HTML for hypertext.
CSV (Comma Separated Values) for tabular data.
|Is self-describing, i.e., contains embedded metadata that help interpret the context and structure of the data file.||XML (Extensible Markup Language) files contain headers and tags describing the file's content.|
|Contains as much of the original information as possible.||Motion JPEG 2000, a “lossless” format for digital video.|
|FAQs about selecting sustainable formats.||National Archives|
|FAQs about digital audio and video formats.||National Archives|
|Sustainability of Digital Formats||Library of Congress|