On 20 Dec 2016, at 16:49, Adam Roach wrote:
On 12/15/16 22:28, Ben Campbell wrote:
The gotcha is that RFC 4588 would not be possible as an informational 
today; it would not have standing to register the "cause" parameter. 
But at the time it was published, there was a lack of clarity around 
the "standards action" policy for the SIP URI parameters registry.
I don't think that's true. We're talking about a registry established 
by RFC 3969, which says:
  "SIP and SIPS URI parameters and values for these parameters MUST be
   documented in a standards-track RFC in order to be registered by
   IANA."
...and...
  "For the purposes of this registry, the parameter for which IANA
   registration is requested MUST be defined by a standards-track 
RFC."
These are not ambiguous statements. We just botched our communication 
with IANA.
For the record, I did not say the RFC was ambiguous. I said "we had a 
lack of clarity". I think having one policy listed in IANA and another 
in the RFC counts. I offer as evidence of said lack of clarity the fact 
that RAI got things wrong with 4458 (My typo of it as 4588 above 
upthread couldn't help, either) :-)
But I think we can do the right thing here without going back and 
fixing all of the issues with our ancestral documents. I mean, sure, 
maybe we should clean that up too, but I don't see the value in 
blocking new work on doing so.
In terms of publishing draft-mohali-dispatch-cause-for-service-number, 
I think there are two reasonable paths forward:
The first would be forming consensus that the two statements I quote 
from 3969 above -- and the reinforcing statement in 5727 -- were all 
incorrect, and that we want to explicitly (i.e., in a new document) 
reverse those statements and update the corresponding registration 
policy. Then, we publish -mohali- as informational.[1]
The second would be implicitly accepting established consensus around 
this registry, and consequently changing -mohali- to PS.
I think a potential third option is to consider whether -mohali- really 
needs to modify the registry. (I'm not saying it doesn't--I'm saying we 
should think about it.)
Rather than figuring out which of these is easier (clearly, the second 
is less work), I think the real question here is: do we think we got 
the registration policy for SIP URI parameters wrong?
Keep in mind that the registry is not the only concern mentioned so far. 
Both 4458 and -mohali- define protocol. Reviewers have objected to that 
as well.