> For the complete documentation index, see [llms.txt](https://docs.b2ihealthcare.com/snow-owl-authoring-platform/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.b2ihealthcare.com/snow-owl-authoring-platform/editing-and-authoring/evaluating-changes/concept-history.md). # Concept History 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](/files/WoMVXtuWTaOFJjLcwhvK) * 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. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.b2ihealthcare.com/snow-owl-authoring-platform/editing-and-authoring/evaluating-changes/concept-history.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.