diff --git a/osu.Game/Rulesets/Edit/PlacementMask.cs b/osu.Game/Rulesets/Edit/PlacementMask.cs
index a588a9e181..be2c42b586 100644
--- a/osu.Game/Rulesets/Edit/PlacementMask.cs
+++ b/osu.Game/Rulesets/Edit/PlacementMask.cs
@@ -15,6 +15,9 @@ using OpenTK;
 
 namespace osu.Game.Rulesets.Edit
 {
+    /// <summary>
+    /// A mask which governs the creation of a new <see cref="HitObject"/> to actualisation.
+    /// </summary>
     public abstract class PlacementMask : CompositeDrawable, IRequireHighFrequencyMousePosition
     {
         /// <summary>