Xasima is right.

It isn't part of XML.  It is way to apply XML.  
XML doesn't care.  Claims like this make it hard 
to know what XML is or isn't good for, what are 
reasonable claims for changes to XML, and so on. 
It also screws up history and in the giant 
amplifier of perceptions driving acts that is the 
web, that is an unhealthy practice.

It is a 'myth' that 'it is a part of XML'.  It isn't 
a myth that it's a smart thing to do; it means 
things like XMLhttp objects, hidden frames, etc., 
come about.  You can do it without XML, but XML, 
per agreement about the syntax, makes it practical 
to do at a very large scale per agreement.

len


From: Doug Rudder [mailto:drudder@d...]

It's not a myth; it's a very useful and important part of XML. But only a
part, and not always required, as you noted. Where I work, the separation of
presentation and content is an integral part of what we do in repurposing
content for a variety of print and electronic outputs and even
reusing/mixing pieces and parts to create new products -- and we had to
learn it the hard way. We worked hard to get our authors and editors to quit
thinking about specific presentation and focus on content and structure
(it's a fragile thing still); please, please don't tell them it's just a
myth!