>From http://www.w3.org/TR/xml-id/
"""An xml:id processor must assure that the following constraints hold for all xml:id attributes: The normalized value of the attribute is an NCName according to the Namespaces in XML Recommendation which has the same version as the document in which this attribute occurs (NCName for XML 1.0, or NCName for XML 1.1).""" Doesn't this mean you can't use a URI as an ID? -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Daniel Aleksandersen Sent: Wednesday, January 30, 2008 1:41 PM To: Atom emailing list Subject: atom:id element vs. xml:id attribute Hi emailing list, (message contains Unicode characters) Why does Atom use a special id element for identification instead of relying on the xml:id attribute? Currently, I apply an identical value to both. <feed … xml:id="urn:uuid:1"> <id>urn:uuid:1</id> <entry xml:id="urn:uuid:2"> <id>urn:uuid:2</id> </entry> </feed> The xml:id attribute makes parsing easier in a lot of environments— especially in PHP 5 DOM XML—, but since the Atom format requires an id element; I have to include that as well. What decision lead to the inclusion of the required atom:id element instead of the xml:id? Is there a point I am missing somewhere? xml:id is perfectly capable of performing the task of atom:id. I cannot see why there would be any need for any special id element in any XML format when we have got xml:id. -- Daniel Aleksandersen <[EMAIL PROTECTED]>
