Ping @reactive-streams/contributors

s/upsteam/upstream a typo.

Agreed on removing the test. Not sure I understand why the appendix addition is needed or beneficial. Lots of choices exist when implementing this stuff, we don't need to itemize them.

@benjchristensen upsteam sounds a bit cool tho...

The appendix addition is definitely useful for implementors that may or may not know what can be done.
Since it is rather clear that it is not a spec rule I see no harm in adding it. @smaldini asked to have it added so he'll probably want to comment.

I agree that deleting that one makes sense, thanks @viktorklang.
No hard feelings on the appendix though - maybe it would become a tips section at some point rather than a sentence here. For now is fine as is IMO.

16 days later, ping @reactive-streams/contributors

It's fine to commit ... agree with this sentiment -> "maybe it would become a tips section at some point rather than a sentence here"

👍

@benjchristensen Absolutely. It would be great to have an "Implementor's Notes" document.