Section 13.2 about mls-protocol

[bifurcation]

The overall vibe here is that the committer has a free hand in choosing which proposals go into a Commit, but there are certain things they can't do. Thus the negative framing. But obviously given DeMorgan's law, the two formulations are equivalent.

In the spirit of minimizing changes at this late stage, I would propose closing without action.

[rohan-wire]

I got some feedback from our implementors that this language was quite useful. When you are implementing a specific feature set for a deadline, what you are going to send is a small subset of the things that you might receive in the future. Having a negative list like this makes the validation logic clear.

Also, the amount of text required to write the corresponding positive list probably runs more than twice as long.

[paulwouters]

that's fine with me