diff --git a/Foundation/CPArray.j b/Foundation/CPArray.j
index 240bfc41e..5efcb9392 100755
--- a/Foundation/CPArray.j
+++ b/Foundation/CPArray.j
@@ -1206,6 +1206,9 @@
 @end
 
 /*!
+    @class CPMutableArray
+    @ingroup compatability
+
     This class is just an empty subclass of CPArray.
     CPArray already implements mutable methods and
     this class only exists for source compatability.
diff --git a/Foundation/CPAttributedString.j b/Foundation/CPAttributedString.j
index f0aef8981..3faabf03b 100644
--- a/Foundation/CPAttributedString.j
+++ b/Foundation/CPAttributedString.j
@@ -796,6 +796,9 @@
 @end
 
 /*!
+    @class CPMutableAttributedString
+    @ingroup compatability
+
     This class is just an empty subclass of CPAttributedString.
     CPAttributedString already implements mutable methods and
     this class only exists for source compatability.
diff --git a/Foundation/CPDictionary.j b/Foundation/CPDictionary.j
index 11e7d7656..0233f439a 100755
--- a/Foundation/CPDictionary.j
+++ b/Foundation/CPDictionary.j
@@ -597,6 +597,9 @@
 @end
 
 /*!
+    @class CPMutableDictionary
+    @ingroup compatability
+
     This class is just an empty subclass of CPDictionary.
     CPDictionary already implements mutable methods and
     this class only exists for source compatability.
diff --git a/Foundation/CPIndexSet.j b/Foundation/CPIndexSet.j
index f711cabc6..30aef604d 100644
--- a/Foundation/CPIndexSet.j
+++ b/Foundation/CPIndexSet.j
@@ -819,6 +819,9 @@ var CPIndexSetCountKey              = @"CPIndexSetCountKey",
 @end
 
 /*!
+    @class CPMutableIndexSet
+    @ingroup compatability
+
     This class is an empty of subclass of CPIndexSet.
     CPIndexSet already implements mutable methods, and
     this class only exists for source compatability.
diff --git a/Foundation/CPSet.j b/Foundation/CPSet.j
index e2a214ec6..66556519f 100644
--- a/Foundation/CPSet.j
+++ b/Foundation/CPSet.j
@@ -484,6 +484,9 @@ var CPSetObjectsKey = @"CPSetObjectsKey";
 @end
 
 /*!
+    @class CPMutableSet
+    @ingroup compatability
+
     This class is just an empty subclass of CPSet.
     CPSet already implements mutable methods and
     this class only exists for source compatability.
diff --git a/Foundation/Foundation.j b/Foundation/Foundation.j
index cf2719ef9..a96bc8353 100755
--- a/Foundation/Foundation.j
+++ b/Foundation/Foundation.j
@@ -70,4 +70,5 @@
 
     @defgroup appkit AppKit
     @defgroup foundation Foundation
+    @defgroup compatability Cocoa Compatability
 */