Hello, RTG-Dir asked me to review the newest release of draft-ietf-idr-sr-policy-seglist-id.

The draft reads easy and clear, there is just the 3rd paragraph of chapter 2.1 that puzzles me a bit with its seemingly contradicting combination of MUST and MUST NOT.

The TLV MUST NOT appear twice... okay, so if it appears more than once something we don't understand is going on.
After that we get told what to do if it happens... so it is allowed to appear more than once?
And we are not allowed to consider the TLV malformed, which seem to contradict the first MUST NOT.

If we know what to do with multiple of these TLVs, maybe the first condition should be downgraded to "SHOULD NOT"? If more than one is unacceptable, maybe accepting them anyways is not okay?
If the described combination is right, maybe some additional clarification is needed?