Subject: [sipcore] A new SIP header fields with "P-" name

From: Ivo Sedlacek <[email-masked]>
Date: Tue, 1 Dec 2015 07:00:33 +0000

Hello,

in the last 3GPP CT1 WG meeting, 3GPP CT1 WG was unable to conclude whether it is possible to define and to use a new "P-"header field.

Some believed that IANA registration of a new "P-" header field is not possible any more due to RFC5727. Others believed that IANA registration of a new "P-" header field is possible as long as someone already implemented and deployed such header field  (even if it was done recently).

Can you please provide guidance whether IANA registration of a new "P-" header field is likely? Thanks.

RFC5727 states:

---------------------------

New

   proposals to document SIP header fields of an experimental or private

   nature, however, shall not use the "P-" prefix (unless existing

   deployments or standards use the prefix already, in which case they

   may be admitted as grandfathered cases at the discretion of the

   Designated Expert).

---------------------------

Kind regards

Ivo Sedlacek