Namespace for URI Templates?

I was giving some thought to Joe Gregorio’s latest draft of URI Templates and considering how to use them with paginated feeds.

For example, I have an Atom Feed that includes the following link elements:

<link rel="first" type="application/atom+xml;type=feed" href=""/>
<link rel="last" type="application/atom+xml;type=feed" href=""/>
<link rel="previous" type="application/atom+xml;type=feed" href=""/>
<link rel="next" type="application/atom+xml;type=feed" href=""/>

It’s obvious that, to traverse the Feed, the Client need only change the “idx” parameter. So, why not tell the Client that they can do this with a URI Template?

To do this, I could use a template element, but in what namespace? That’s where my problem comes in.

I’ve searched all over the W3C URI mailing list, in addition to the Atom lists and all the usual suspects, but I haven’t seen where anyone has made a formal a recommendation.

I did stumble across a post by James Snell in which he proposed an approach to create a namespace to describe URI template variable names, but the post is stale (October 2006) and the approach doesn’t address the template itself.

So, without a good lead to go on and a strong desire not to create my own namespace, I sent an e-mail to Mark Nottingham asking if he would be interested in considering an update of the fh namespace to include a template element for this purpose?

For example:


But then I found recent post by Joe Gregorio that doesn’t specifically address this, but does include in one of his examples the following snippet, defining a “t” namespace for the link_template element.

<?xml version="1.0"?>
<entry xmlns=""
<t:link_template rel="sub" href="{-listjoin|;|id}"/>

I don’t know how I feel about having a general purpose template element in a separate namespace rather than having various namespaces define their own template elements. In the fh:template example, the template is within the “feed history” namespace, which gives it meaning; the URI template provided is for feed histories. If there is a separate namespace, then the template can lose context.

So, what do you think? Should there be a separate XML namespace to define URI templates? Is there an effort to do so, and where is the discussion occurring if there is?