@@ -49,10 +49,13 @@
  *
  * Keys are copied and thus must conform to the OFCopying protocol.
  *
  * @note Fast enumeration on a dictionary enumerates through the keys of the
  *	 dictionary.
+ *
+ * @note Subclasses must implement @ref objectForKey:, @ref count and
+ *	 @ref keyEnumerator.
  */
 @interface OFDictionary OF_GENERIC(KeyType, ObjectType): OFObject <OFCopying,
     OFMutableCopying, OFCollection, OFSerialization, OFJSONRepresentation,
     OFMessagePackRepresentation>
 #if !defined(OF_HAVE_GENERICS) && !defined(DOXYGEN)