Federal Records Management

AC 23. 2020

AC 23.2020

August 5, 2020


I am pleased to announce that NARA has added Electronic Navigational Chart (ENC) and Raster Navigational Chart (RNC) file formats to Appendix A: Table of File Formats of NARA Bulletin 2014-04, Format Guidance for the Transfer of Permanent Records. 
Electronic navigational charts are tools used to provide safe navigation for all classes of vessels. Official charts are issued by government hydrographic offices or other institutions, and comply with standards developed by the International Hydrographic Organization (IHO). These charts show detailed configurations of the seabed, characteristics of the coast, routes, and aids to navigation.
There are two types of electronic navigational charts—raster charts and vector charts:

  • Electronic Navigational Charts (ENC) are vector data sets of all the objects (points, lines, and areas) represented on a chart in a digital database.
  • Raster Navigational Charts (RNC) are digitized raster copies of official paper charts.


NARA Bulletin 2014-04 uses the Appendix to specify which file formats are acceptable when transferring permanent electronic records to NARA. As stated in the bulletin, the Appendix will be updated to include acceptable formats and reflect the continual format changes in how agencies create and use electronic records. 
If you have any questions, please email rm.standards@nara.gov.
Chief Records Officer
for the U.S. Government