[Cellar] namespace considerations for ebml's definition of EBML Schema

[Dave Rice <[e-mail]>]

Hi cellar,
This is a late comment in regards to the EBML document, but I’m considering this dialogue.

>>>>>>> Begin forwarded message:
> 
> From: Karen Moore <[e-mail]>
> Subject: [AD - Murray] Re: AUTH48 [KC][SW]: RFC 8794 <draft-ietf-cellar-ebml-17.txt> NOW AVAILABLE
> Date: July 16, 2020 at 1:53:35 PM EDT
> To: "Murray S. Kucherawy" <[e-mail]>, Steve Lhomme <[e-mail]>, Dave Rice <[e-mail]>, Moritz Bunkus <[e-mail]>
> Cc: RFC System <[e-mail]>, Alexey Melnikov <[e-mail]>, [e-mail], [e-mail], Steven Villereal <[e-mail]>
> 
>>>>>>>> 3) In the XML Schema for EBML Schema, the URL https://ietf.org/cellar/ebml <https://ietf.org/cellar/ebml>
>>>>>>>> is provided, but it doesn't seem to be a valid site. Please confirm that this
>>>>>>>> is okay.
>>>>>>>> -->
>>>>>>> 
>>>>>>> I don't suppose we could host it on the IETF website. I'm not sure if
>>>>>>> a valid URL is necessary here, this is just a marker for a namespace.
>>>>>>> I think it only needs to be unique so that it's not mistaken with an
>>>>>>> XSD with a same name.

Within the EBML Schema example xml and the EBML Schema XSD the value of https://ietf.org/cellar/ebml <https://ietf.org/cellar/ebml> is used as an undefined and stand-in namespace. From reviewing other RFCs which define XML Schemas, I see that they don’t use this style of URL but instead use a URN guided by RFC2648.

Should we consider adding a section such as the one quoted below and changing from https://ietf.org/cellar/ebml to urn:ietf:params:xml:ns:ebml?

> ### `<EBMLSchema>` Namespace
> 
> The namespace URI for elements defined by this specification is a URN as
> defined by [@!RFC2141] that uses the namespace identifier 'ietf' defined by
> [@!RFC2648] and extended by [@!RFC3688]. This URN is:
> 
> ```
> urn:ietf:params:xml:ns:ebml
> ```

and changing from https://ietf.org/cellar/ebml to urn:ietf:params:xml:ns:ebml. This would follow the recommendation at https://tools.ietf.org/html/rfc3470#section-4.9 <https://tools.ietf.org/html/rfc3470#section-4.9>.

Dave Rice