diff --git a/src/NCollection/NCollection_DataMap.hxx b/src/NCollection/NCollection_DataMap.hxx
index 779bdecea6..e3bdb3fb2d 100644
--- a/src/NCollection/NCollection_DataMap.hxx
+++ b/src/NCollection/NCollection_DataMap.hxx
@@ -214,9 +214,10 @@ public:
     }
   }
 
-  //! Bind binds Item to Key in map. Returns Standard_True if Key was not
-  //! exist in the map. If the Key was already bound, the Item will be rebinded
-  //! and Standard_False will be returned.
+  //! Bind binds Item to Key in map.
+  //! @param theKey  key to add/update
+  //! @param theItem new item; overrides value previously bound to the key, if any
+  //! @return Standard_True if Key was not bound already
   Standard_Boolean Bind (const TheKeyType& theKey, const TheItemType& theItem)
   {
     if (Resizable()) 
diff --git a/src/NCollection/NCollection_IndexedDataMap.hxx b/src/NCollection/NCollection_IndexedDataMap.hxx
index 45fa17dc01..b6c3684023 100644
--- a/src/NCollection/NCollection_IndexedDataMap.hxx
+++ b/src/NCollection/NCollection_IndexedDataMap.hxx
@@ -241,7 +241,10 @@ private:
     }
   }
 
-  //! Add
+  //! Returns the Index of already bound Key or appends new Key with specified Item value.
+  //! @param theKey1 Key to search (and to bind, if it was not bound already)
+  //! @param theItem Item value to set for newly bound Key; ignored if Key was already bound
+  //! @return index of Key
   Standard_Integer Add (const TheKeyType& theKey1, const TheItemType& theItem)
   {
     if (Resizable())