> ## 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. # Edit a Vantage skill in Advanced Designer > Open a skill from Vantage's Skill Catalog in Advanced Designer to add custom activities, refine extraction, or build on a derived skill. Open a skill from the Vantage **Skill Catalog** in Advanced Designer to add custom activities or refine extraction. The two starting points below cover the most common edits. ## Edit a derived skill Vantage built-in skills and read-only skills published by third-party developers cannot be edited directly. Instead, create a [derived skill](/vantage/documentation/advanced-designer/document-skills/derived) from the base skill and edit the derived skill. Derived skills inherit all rules and fields from their base skill and can be updated to new versions of the base while preserving your changes. Once the derived skill exists, edit it using the same procedure as **Edit a custom skill** below. ## Edit a custom skill If a custom skill's extraction quality isn't good enough, add or reconfigure activities — for example, an [Extraction Rules activity](/vantage/documentation/advanced-designer/activities/extraction-rules/extraction-rules) to fine-tune specific fields, or an [Address Parsing activity](/vantage/documentation/advanced-designer/activities/address-parsing) to break down a full address extracted by the existing flow. Advanced Designer skill processing flow with a Fast Learning activity followed by an Extraction Rules activity On the start page, select the skill in the **Skill Catalog**. The document set appears on the **Documents** tab — add more images if needed. The field structure and labeling appear on the **Fields** tab. On the **Activities** tab, find the existing [Fast Learning activity](/vantage/documentation/advanced-designer/activities/fast-learning), which uses Vantage machine learning to extract fields. Add an [Extraction Rules activity](/vantage/documentation/advanced-designer/activities/extraction-rules/extraction-rules) to set up custom object search conditions. To target only specific fields, list them under the **Activities** tab of the Properties pane on the new activity. Click **Activity Editor**. Use sample documents to set up the extraction rules so that every targeted element is detected correctly. Close the **Activity Editor** and click **Test Skill Using Selected Documents** to evaluate the results. When the results are good enough, [publish the skill](/vantage/documentation/advanced-designer/document-skills/publish). ## Related activities Build a new skill on top of a built-in or read-only Vantage skill. Add rule-based extraction on top of the existing Fast Learning flow. Split addresses extracted by the skill into street, city, state, country, postal code. The activity already in the flow when you open a Vantage-built skill in Advanced Designer.