CEP 26: Potential improvements

[jaimergp]

@mbargull added this review a bit before the voting deadline ended, so I'm capturing it here so we can address it a future revision.

I'm very thankful that you continue to work on/write up how specification-like documents for all these previously only "implementation-defined" (and thus bound to be diverging) workings.

I vote to accept this proposal since it is a very good starting point to align implementations in package managers as well as distribution tools overall.

Unfortunately I wasn't able to take part in the discussion beforehand (but expect to be able to in the near future), so I apologize to not have given input before.
There are certain points (channel name/label definition, maximum length of package name/version/buildstring, etc.) that are either different from current definitions or possibly too restrictive.
E.g., maximum component lengths are worded with MUST NOT exceed even though we have existing cases that do exceed the given limits already -- hence it might make sense to have higher MUST NOT exceed limits and possibly have the current lower limits declared as SHOULD NOT exceed.
In my eyes in makes sense to declare this proposal as "provisional" since adjusting implementation to be "compliant to CEP XXXX" could be counter productive until those points have been worked on in later refinements to this proposal.

Originally posted by @mbargull in #116 (review). See also comments under this review.