Identifying streams more precisely

Two issues were raised about the use of the words "existing" and "current" to refer to streams.  These were a little squishy, so I tightened the language a little.  The text no longer uses either word to refer to streams, instead using stream states to describe where the relevant text applies and favouring "identified" as a fallback.
Ahh, yes.  I will drop the specific stream states from this specific statement (less text FTW).