<!-- [rfced] Section 13.2.1. We are having difficulty parsing the
following. Would reordering improve readability?
Current:
A server MUST ignore all received preconditions if its response to
the same request without those conditions, prior to processing the
request content, would have been a status code other than a 2xx
(Successful) or 412 (Precondition Failed).
Perhaps:
If a server would have responded to the same request lacking
those conditions with a status code other than a 2xx (Successful)
or 412 (Precondition Failed) prior to processing the request content,
then the server MUST ignore all received preconditions.
-->