* Source elements, demuxers and other elements that create new streams
* are supposed to send this event as the first event of a new stream. It
* should not be send after a flushing seek or in similar situations
- * and is used to mark the beginning of a new logical stream.
+ * and is used to mark the beginning of a new logical stream. Elements
+ * combining multiple streams must ensure that this event is only forwarded
+ * downstream once and not for every single input stream.
*
* Returns: (transfer full): the new STREAM_START event.
*/