<p></p>
<p dir="auto"><a class="user-mention notranslate" data-hovercard-type="user" data-hovercard-url="/users/miconda/hovercard" data-octo-click="hovercard-link-click" data-octo-dimensions="link_type:self" href="https://github.com/miconda">@miconda</a> I think this is the relevant table in section 20 <a href="https://datatracker.ietf.org/doc/html/rfc3261#section-20" rel="nofollow">link</a></p>
<p dir="auto">Seems to be pretty clear, if I read it correctly.</p>
<pre class="notranslate"><code class="notranslate"> -: The header field is not applicable.
"Not applicable" means that the header
field MUST NOT be present in a request. If one is placed in a
request by mistake, it MUST be ignored by the UAS receiving the
request. Similarly, a header field labeled "not applicable" for a
response means that the UAS MUST NOT place the header field in the
response, and the UAC MUST ignore the header field in the response.
</code></pre>
<pre class="notranslate"><code class="notranslate"> Header field where proxy ACK BYE CAN INV OPT REG
___________________________________________________________
Contact R o - - m o o
Contact 1xx - - - o - -
Contact 2xx - - - m o o
Contact 3xx d - o - o o o
Contact 485 - o - o o o
</code></pre>
<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />Reply to this email directly, <a href="https://github.com/kamailio/kamailio/pull/3149#issuecomment-1161330436">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/ABO7UZIRA4E2P5AVH4VZIKLVQFQPPANCNFSM5ZET6XGQ">unsubscribe</a>.<br />You are receiving this because you are subscribed to this thread.<img src="https://github.com/notifications/beacon/ABO7UZOHETEMQYSUSFC3Z5LVQFQPPA5CNFSM5ZET6XG2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOIU4H6BA.gif" height="1" width="1" alt="" /><span style="color: transparent; font-size: 0; display: none; visibility: hidden; overflow: hidden; opacity: 0; width: 0; height: 0; max-width: 0; max-height: 0; mso-hide: all">Message ID: <span><kamailio/kamailio/pull/3149/c1161330436</span><span>@</span><span>github</span><span>.</span><span>com></span></span></p>
<script type="application/ld+json">[
{
"@context": "http://schema.org",
"@type": "EmailMessage",
"potentialAction": {
"@type": "ViewAction",
"target": "https://github.com/kamailio/kamailio/pull/3149#issuecomment-1161330436",
"url": "https://github.com/kamailio/kamailio/pull/3149#issuecomment-1161330436",
"name": "View Pull Request"
},
"description": "View this Pull Request on GitHub",
"publisher": {
"@type": "Organization",
"name": "GitHub",
"url": "https://github.com"
}
}
]</script>