When SNOMED CT content is promoted from an extension module into a less dependent module (e.g. the international edition) to enable broader use, specific changes occur in the RF2 files of the associated SNOMED CT releases. In this section, we provide examples of how the relevant RF2 release files are changed when a concept is promoted and explain how the resulting files are used.

Distribution Approaches

SNOMED CT is distributed to users using one of two main approaches:

1. As a SNOMED CT edition, in which the SNOMED CT extension content is combined together with the files from the International Edition (and any other dependent module)
2. As a SNOMED CT extension, which contains only the new content added into the extension. To deploy a SNOMED CT extension, it must be combined with the international versioned edition that it is dependent on (and any other dependent modules), and any conflicts resolved (as explained below).

The diagram below illustrates these two approaches. In each approach, 3 release file types are distributed - the

Concept Promotion Scenario

In the following sections, we illustrate how each of the Concept files would appear both before and after the promotion of the fictitious concept 

In these examples, we will assume that the 

• Created in the 

  Concept
  t Extension module (foundation metadata concept)

   on 31st September 2018
• Updated in the 

  Concept
  t Extension module (foundation metadata concept)

   on 31st March 2020
• Promoted to the 

  Concept
  t SNOMED CT core module (core metadata concept)

   on the 31st July 2020

We also assume the following dependencies:

• Before promotion: The 31st March 2020 version of the National Extension is dependent on the 31st January 2020 International Edition
• After promotion: The 31st September 2020 version of the National Extension is dependent on the 31st July 2020 International Edition

In the following section, we will first illustrate the changes using the SNOMED CT edition distribution method. And in the subsequent section, we will illustrate these changes using the SNOMED CT extension distribution method. In both cases, we will consider the impact to all three release file types - the

Concept Promotion using Edition Distribution

In this section, we illustrate the changes to the release files when promoting a concept using the edition distribute method.

Full Release File

Before Promotion

After Promotion

Snapshot Release File

Before Promotion

After Promotion

Delta Release File

Before Promotion

After Promotion

Concept Promotion using Extension Distribution

In this section, we illustrate the changes to the release files when promoting a concept using the extension distribute method.

Full Release File

Before Promotion

After Promotion

Snapshot Release File

Before Promotion

After Promotion

Delta Release File

Before Promotion

After Promotion