Doc.

modules/core/events.py

@@ -170,7 +170,7 @@ class EngineEventDispatcher():
         and passes an `PlaylistEntry` to event handlers.
 
         Args:
-            source (String):    The `Entry` or URI or of the media source currently being played
+            source (String):    The `Entry` object *or* the URI of the media source currently playing
         """
         self.logger.debug("on_play(..)")
         entry = None