Also, I don't see the value of the last sentence in this paragraph, especially with RFC2119 MAY.
This section defines several stream schedulers. The stream
schedulers may behave differently depending on whether user message
interleaving has been negotiated for the association or not. An
implementation MAY implement any subset of them.
During the review the question was brought up which scheduler have to be implemented
by an implementation. This sentence was add to address it.
If you want, I can remove it.
The point is that the MAY is that sentence doesn't mean anything.
Maybe you mean:
An implementation MUST implement at least one stream scheduler.
That would require an implementation to implement at least one of
the ones being listed. You are right in the sense that an implementation
MUST implement at least one stream scheduler, but the original text
allows that one not to be specified in this document.
Are you saying that an implementation MUST implement one of list defined
by this document?
I'm saying that "An implementation MAY implement any subset of them." as
a sentence doesn't make sense.
Are we going in circle here?
Regards, B.