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NIEM 5.0 Release Candidate 4 Available for Public Review and Comment

The NIEM 5.0 release candidate 4 (RC4) is available for public review and comment through Monday, 19 October 2020. The RC4 incorporates the feedback received from the NIEM 5.0 release candidate 2 (RC2) and release candidate 3 (RC3). These minor changes include:

  • Updated GENC CSV files to exclude GENC codes marked ‘exclusion’
  • Updated GENC enumerations to exclude GENC codes marked ‘exclusion’
  • Added “SP-“ to the beginning of CUI specified category marking codes
  • Removed CUI “NATO Restricted” and “NATO Unclassified” category codes
  • Updated cardinality to support CUI multiple dissemination controls
  • Created a substitution group for CUI RELTO codes
  • Updated the names and definitions of CUI limited dissemination RELTO elements to represent both RELTO and DISPLAY ONLY options
  • Updated CUI category and limited dissemination control codes based on registry updates
  • Updated GENC codespace identifiers and local terminology

Please visit the NIEM Releases page for instructions on how to download the RC4 package. Please provide feedback by submitting a new 5.0 issue or by sending an email to by Monday, 19 October 2020

At this point in the release cycle, we are working to get to a stable draft and are looking to address errors and bugs only. Other issues can be queued up for the next release. The final release of NIEM 5.0 is scheduled to be published this fall. At that time, 5.0 XML schemas and documentation will be published along with updates to NIEM specifications and tools.