One objective of the archiving program is to minimize the effort required to maintain the data publication. In part, this means trying to avoid maintaining versions of the data in multiple formats or updating formats periodically. Another objective is to make the data and metadata as accessible as possible across computing platforms, again while minimizing the use of multiple file formats.

These objectives and NARA recommendations have led to the following typical file formats for data we publish:

• Tabular data
  • CSV (comma-delimited text)
  • TXT (text)
  • XLSX (Office Open XML)
• GIS data
  • TIF (georeferenced TIFF file)
  • SHP (shapefile; older format that we stopped using in 2021)
  • GPKG (OGC GeoPackage; modern replacement for shapefile)
  • GDB (geodatabase)  
• Database files
  • MDB (Access database)
  • SQLite (relational database)
• Text documentation
  • PDF  
  • TXT
• Images*
  • JPEG
  • PNG
  • TIFF
• Audio*
  • MPEG-3 (MP3)
• Video*
  • MPEG-4 (MP4)

*prefer lossless when possible