I am the assigned ART directorate reviewer for this document. These comments
were written primarily for the benefit of the ART area directors.  Document
editors and WG chairs should treat these comments just like any other last call
comments.

I reviewed the -09 version of the draft before. Some of my concerns were addressed 
in the -10 version. I still have the following issues with the document.

1) It is not clear from the document if it is ever possible for clients 
that support only version x of the protocol to join the group that was formed using version y
of the protocol, but in fact all the current members of this group support both versions.
It seems to me that this scenario is common in situations when newer version of the protocol
becomes available: during some period of time some clients will support both new and old version, 
while the rest will support only old version. If some upgraded clients form a group, they will
probably choose the newest version of the protocol, so the un-upgraded clients won't be able
to join it. I think that this scenario should be addressed in the document. 

2) It is still not clear for me whether the type of DS (Strongly Consistent vs Eventually Consistent)
affects clients that use this DS. In other words - does clients' behaviour depend on the type of DS or not,
and if yes, then how it is handled in the protocol.

3) The issue of inability for a client to remove itself from the group by itself seems unsolvable.
I would like to see recommendations in the document for clients wishing to exclude themselves 
in situations when other members for some reasons don't cooperate in this process.

While I think these issues are important, I'd leave them on ADs' discretion.