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Deprecation Notice: SNOMED CT Release Format 1 (RF1)

On Wednesday, 28 October 2015, the IHTSDO General Assembly voted to approve the deprecation of SNOMED CT Release Format 1 (RF1). Key dates in the deprecation are:

  • January 2016: Updated RF2 to RF1 conversion utility is made available to the public on IHTSDO MLDS site.
  • July 2016: Final RF1 release by IHTSDO.
  • January 2017: RF1 users obtain files by converting them from RF2.

The reason IHTSDO decided to deprecate the artifact was as follows:

RF1 was replaced by Release Format 2 (RF2) as the authoritative distribution format for the SNOMED CT International Edition in July 2011. Only one-ninth of IHTSDO Members currently use the outdated distribution format. IHTSDO no longer has a business case for allocating resources to maintain and mitigate risks associated with the outdated format. In addition, RF1 has well documented design flaws. Its derivation from RF2 introduces potential safety risks, resulting from possible anomalies in the manually curated Compatibility Package. The design flaws have been corrected in RF2. By deprecating these obsolete artifacts, IHTSDO will reduce risk and save resources, and it will be able to focus on a more streamlined, accurate, efficient and safe product line.

For further information or assistance, please see or contact IHTSDO at

© International Health Terminology Standards Development Organisation 2016. All rights reserved. SNOMED CT® was originally created by the College of American Pathologists.

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