I didn&#x27;t know about that, thanks.<p>Then I looked for the sanctioned meaning of &quot;ought to&quot; and found <a href="https:&#x2F;&#x2F;www.ietf.org&#x2F;rfc&#x2F;rfc6919.txt" rel="nofollow">https:&#x2F;&#x2F;www.ietf.org&#x2F;rfc&#x2F;rfc6919.txt</a><p>&quot;The phrase &quot;OUGHT TO&quot; conveys an optimistic assertion of an implementation behavior that is clearly morally right, and thus does not require substantiation.&quot;<p>But it&#x27;s dated 1st April 2013 so that&#x27;s a dead end :-)<p>Still I think that &quot;ought to&quot; in RFC 7231 is close to what 6919 &quot;prescribed&quot; or they would have used MUST or SHALL. Furthermore there is the matter of history and URL autocompletion. I don&#x27;t know if it should be OK to rewrite history. I&#x27;m fine with handling all of that manually.