Snow Owl supports importing the full release of SNOMED CT, including historical data on every component change since 2002. The History View provides information about the changes made to a given concept over time. By default, it is linked to the active editor or the selection in the currently active SNOMED CT Concepts View or Parents View.
History View for SNOMED CT Root Concept
The table in the upper part of the view shows the revisions that the concept went through. It displays the version number, date, number of changes, name of the author, and comments (e.g. if it was a full or a delta import).
Clicking on an item reveals further information in the bottom section. You can see which components were modified and the kind of changes that were made.
Historical concept information from the SNOMED CT RF2 Association type Reference Set can also be imported and displayed. This includes details about why a concept was inactivated and suggestions for alternate concepts that replaced an inactive concept. To navigate to the related concept, click the hyperlink in the editor.