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NIEM 5.1 Release Candidate 2 Available for Public Review and Comment

The NIEM 5.1 Release Candidate 2 (RC2) is available for public review and comment thru Wednesday, December 8, 2021. Visit the NIEM Releases page for instructions on how to download the RC2 package.  Please provide your feedback by submitting a new issue or by sending an email to

The most recent changes include:

  • Updated Biometrics definition and restored DNAPedigree components from 4.1
  • Added new Controlled Unclassified Information (CUI) limited dissemination code "RELIDO"

This is the final stage before the final NIEM 5.1 release will be officially published. 

About NIEM
The National Information Exchange Model (NIEM) provides a model framework with rules and guidance designed to develop consistent, well-defined, enterprise level information exchanges. NIEM successfully supports communities of interest with a shared need to exchange data within federal, state, local, tribal, and territorial agencies, internationally, and in the private sector.
To learn more, please visit