I'd like to add a sub-space for implementations to use for their implementation-specific things. Nice thing about a URN is that it can specify a structured scheme for this:

I suggest "imp" as a sub-specifier for implementation-specific URNs.  E.g., urn:ogf:dfdl:2011:imp:...

What goes after imp is an identifier of an implementation. E.g.,


and beneath that is anything that implementation needs/wants. E.g., a namespace for extension properties that are non-standard, a version ID for sub-versions of that implementation, etc. etc.

This allows an implementation to define extension properties, and have other implementations give warnings that those are detected, but not understood.

...mikeb



On Mon, Oct 29, 2012 at 11:37 AM, Steve Hanson <smh@uk.ibm.com> wrote:
Using the OGF's URN registration document [GFD.191] as a reference, I suggest:
Type URL Proposed URN
common root urn:ogf:dfdl
xmlns attribute http://www.ogf.org/dfdl/dfdl-1.0/ urn:ogf:dfdl:2011
source attribute http://www.ogf.org/dfdl/ urn:ogf:dfdl


[GFD.191] http://www.ogf.org/documents/GFD.191.pdf

Regards

Steve Hanson
Architect, Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh@uk.ibm.com
tel:+44-1962-815848



From:        Suman Kalia <kalia@ca.ibm.com>
To:        Mike Beckerle <mbeckerle.dfdl@gmail.com>,
Cc:        dfdl-wg@ogf.org, dfdl-wg-bounces@ogf.org
Date:        25/10/2012 17:15
Subject:        Re: [DFDL-WG] new action item needed: DFDL URN specification
Sent by:        dfdl-wg-bounces@ogf.org



I tend to agree that  specifying urn for namespaces is better choice and  URL should be used for schema locations; however  convention of specifying URL for namespaces is long established some implementations use the namespace  URL to return  the actual schema.     When I try to access the namespace URL for XML schema , it gives me reference to the document but not schema..  



Suman Kalia
IBM Canada Lab
WMB Toolkit Architect and Development Lead
Tel: 905-413-3923 T/L 313-3923
Email: kalia@ca.ibm.com

For info on Message broker
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From:        Mike Beckerle <mbeckerle.dfdl@gmail.com>
To:        dfdl-wg@ogf.org,
Date:        10/25/2012 08:18 AM
Subject:        Re: [DFDL-WG] new action item needed: DFDL URN specification
Sent by:        dfdl-wg-bounces@ogf.org



I wanted to add to this discussion the w3c blog page that highlights the problem of the http-based naming scheme. There are many articles about this, this is just one of them.

http://www.w3.org/blog/systeam/2008/02/08/w3c_s_excessive_dtd_traffic/

On Wed, Oct 24, 2012 at 10:35 AM, Mike Beckerle <mbeckerle.dfdl@gmail.com> wrote:

Introduction:

Using URLs as identifiers has caused no end of problems. E.g., in DFDL we have http://www.ogf.org/dfdl/dfdl-1.0/ as an identifier. W3C has http://www.w3.org/2001/XMLSchema and others.

W3C has badly regretted establishing this convention, as they have farms of servers that do nothing but quickly return 404 errors to save network-aware applications the network-timeout delay that would otherwise occur.

There are parties interested in exploiting DFDL who want DFDL schemas to NOT contain network URLs because it simply creates a concern about network access whenever a DFDL schema is inspected/used.

Pre-Proposal:

The new way to do this is with URNs which would look roughly like this: urn:ogf:dfdl:standard:dfdl-1.0. The whole point is that some other mechanism is used to establish correspondences between these and any resources in file systems, networks, or built-in to implementations. One such mechanism is called XML Catalog.

The point is that it is a name in a managed namespace which cannot be confused with a network protocol URL.

OGF is already establishing urn:ogf, and an ogf subgroup has already proposed urn:ogf:network for network resources. DFDL schemas aren't network resources so we don't want to be a substructure underneath network.

Some other mechanism is used to establish correspondences between these and any resources in file systems, networks, or built-in to implementations. One such mechanism is called XML Catalog.

Summary:

An action item should be to specify DFDL urn, submit to OGF as a proposed namespace, and then produce errata/spec changes to specify its use.

This requires a small design activity to specify a scheme for the sub-structure of the DFDL URNs (i.e., scheme for the stuff after urn:ogf:dfdl:...) where we want standard identifiers for versions of the standard, but we probably also want a few other things (e.g., I would like a space for implementations to identify themselves, i.e., an implementation-specific sub-area within our URNs.)

Our existing URLs can be compatible (deprecated) practice vs the preferred URNs.






--
Mike Beckerle | OGF DFDL WG Co-Chair
Tel:  781-330-0412




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Tel:  781-330-0412