#474 add an <exemplum/> for @ref

[stuart yeates]

@ref doesn't currently have an example. Here's a diff

stuartyeates@stuartyeates:/opt/tei$ svn diff 
Index: P5/Source/Specs/att.canonical.xml
===================================================================
--- P5/Source/Specs/att.canonical.xml   (revision 12527)
+++ P5/Source/Specs/att.canonical.xml   (working copy)
@@ -66,6 +66,15 @@
       <datatype minOccurs="1" maxOccurs="unbounded">
         <rng:ref xmlns:rng="http://relaxng.org/ns/structure/1.0" name="data.pointer"/>
       </datatype>

+      <exemplum xml:lang="en">
+   <p>In <ref target="https://github.com/emory-libraries-beckctr/belfast/raw/master/xml/heaney1.xml">Heaney Workshops</ref>, the name 'Seamus Heaney' in a byline is linked to his record in the VIAF authority file using:</p>
+   <egXML xmlns="http://www.tei-c.org/ns/Examples">
+          <back xml:id="heaney1_1014">
+            <byline><name ref="http://viaf.org/viaf/109557338" type="person">Seamus Heaney</name></byline>
+          </back>   
+   </egXML>
+      </exemplum>
+
       <remarks>
         <p>The value must point directly to one or more XML elements by means of one or more URIs,
           separated by whitespace. If more than one is supplied, the implication is that the name

Hopefully the diff doesn't get mangled by the submission form.

[James Cummings]

Submission of an example (with a diff to show the suggested addition) seems uncontroversial. I think a less confusing example (even using the same link doesn't need the additional paragraph of explanation and strange use of byline in back. Just:

<name ref="http://viaf.org/viaf/109557338" type="person">Seamus Heaney</name>

Marking as GREEN and assigning to me.

[James Cummings]

Example added at [r12746]

However, the example points to an html source of information which now makes the remarks provided below incorrect. (Also was already so by the example for @key.)

<remarks versionDate="2008-09-05" xml:lang="en">
 <p>The value must point directly to one or more XML elements by means of one or more URIs, separated by whitespace. If more than one is supplied, the implication is that the name identifies several distinct entities. </p>
</remarks>

In general use of @ref is that people use it sometimes to point to XML element(s) and sometimes to other forms of URI. The @ref attribute provides means of locating a full definition for the entity... there shouldn't be a requirement that this definition should be an XML element.

[Martin Holmes]

How about "must point to one or more XML elements or external resources by means of one or more URIs..."

[James Cummings]

That seems fairly uncontroversial.

[Syd Bauman]

The value must point directly to one or more addressable resources, typically XML elements, by means of one or more URIs,separated by whitespace. If more than one is supplied, the implication is that the name identifies several distinct entities.

[Syd Bauman]

Not sure why, but I have a mild preference for ﹤persName﹥ over ﹤name type="person"﹥.

[James Cummings]

remarks changed at [r12756] closing ticket.