> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Manage skill versions in Advanced Designer
> Manage Advanced Designer skill versions — track published versions, roll back, edit older versions, and configure auto-deletion of older versions.
Each time you publish a skill in Advanced Designer, it gets a new **version number**. A single skill can have many versions, letting you keep variants of the same skill instead of creating separate ones. The version number appears in the **Version** column next to the skill in the [Skill Catalog](/vantage/documentation/skill-catalog/skill-catalog); clicking the number opens the **Skill Versions** dialog with details for every existing version.
## Before and after publishing
Review the skill's extraction statistics before publishing a new version. If the new version performs worse than the previous one:
* **Before publishing** — on the start page, select the skill in the **Skill Catalog** and click the **Discard** icon next to the skill description. The pending changes are dropped and the previous published version remains the active one.
* **After publishing** — edit the skill and publish again, or delete the new version.
## Auto-deletion of older versions
By default, **only the last three versions are kept**. If a skill has more than three versions, older versions that aren't referenced by other skills or transactions are deleted automatically. Toggle off **Keep only 3 latest versions** to disable this and retain every version manually.
## Edit and copy versions
Open the **Skill Versions** dialog (click the version number in the Skill Catalog) to work with specific versions. The latest version is selected by default; the **editable version** is also shown here. A skill can have only one editable version at a time.
To work with a different version, click the more icon next to its number and choose:
* **Edit skill version** — edit the selected version directly.
* **Duplicate skill to create new version** — create a new skill (rather than a new version of the current one) and edit that.
* **Create and Edit Derived Skill** — create a [derived skill](/vantage/documentation/advanced-designer/document-skills/derived) from the selected version.
When you copy a skill, the latest version is copied by default. To copy a different version, click the copy-skill icon or **Duplicate skill to create new version** next to that version. A derived skill can be updated when a new version of its base skill ships.
## Import and export specific versions
**Import.** When importing a skill that already exists in your tenant, you can either import it as a new skill or create a new version of the existing skill. The new version number is incremented from the latest existing version (numbering accounts for every version that has ever existed). Skills imported from another tenant keep their own version numbers.
**Export.** The latest version is exported by default. To export a different version, duplicate the target version first (click the copy-skill icon or **Duplicate skill to create new version**), then export the duplicate.
## Delete a version
To delete a version, click the delete icon next to its number. You can only delete a version that isn't used by other skills or transactions.
Deleted versions cannot be restored. Deleting a skill deletes every version of that skill.
Deleted version numbers are reserved — no new version will ever reuse a deleted number. For example, if you delete version 3 (the latest), the next published version is numbered 4, not 3.
## Related topics
Build a new skill on a chosen version of a built-in or read-only base skill.
Migrate a skill to a newer Technology Core after an app update.
Find, publish, duplicate, import, export, and delete skills.