diff --git a/docs/hyperdatasets/webapp/webapp_datasets_frames.md b/docs/hyperdatasets/webapp/webapp_datasets_frames.md
index 54b2a93f..85e09d21 100644
--- a/docs/hyperdatasets/webapp/webapp_datasets_frames.md
+++ b/docs/hyperdatasets/webapp/webapp_datasets_frames.md
@@ -241,8 +241,28 @@ Filter by sources using Lucene queries.
 
 Use Lucene queries in ROI label filters and frame rules.
         
-## Annotations
 
+## Masks 
+
+Use the **MASKS** panel to select a mask or multiple masks to apply over the frame. 
+
+To view / hide a specific mask, click <img src="/docs/latest/icons/ico-show.svg" alt="Eye Show" className="icon size-md space-sm" />.
+In order to view all masks, click **Show all** / **Hide all**. 
+
+To adjust the transparency of a mask, use its opacity slider. 
+
+### Labels 
+
+The **Active mask labels** section displays the color mapping of the mask labels. 
+The panel presents labels only from masks that are currently displayed.
+
+**To modify a label's color and opacity:**
+1. Click the colored circle next to the label 
+1. Select a new color
+1. Adjust the opacity slider 
+1. Click **OK**
+
+## Annotations
 ### Frame Objects (Regions of Interest)
 
 You can add annotations by drawing new bounding areas, and copying existing annotations in the same or other frames.