Tom Wright wrote:
> Hello
> 
> I'm trying to find an up-to-date reference on units of measure in XML
> documents.  I've found quite a bit of stuff from around 1999-2002 at
> posc.org which refers to a working group at W3C tasked with this problem,
> but I've not found much more recent stuff and can't find anything at w3.org
> or in a search of past messages on this group.
> 
> Is there anything of the sort? Are there any current efforts in this
> direction?  I'd assumed as XML is so widely used that something like this
> would be standardised, so maybe I'm missing the obvious.  Any help would be
> most welcome.

The XML Spec does not address this: it's up to each document type 
designer to add validation criteria in the appropriate places. In a 
recent DTD for a book publisher, I had something like

<!ATTLIST image
   width CDATA #REQUIRED
   units (mm|cm|in|pt|px|pc|pi|cc|dd|sp) "mm">

I could have added meters and feet, but the client doesn't do poster 
work. Equally, a bibliographic application might require sizes in 
characters, lines, paragraphs, pages, signatures, issues, and volumes. 
On the other hand if you were designing for the scientific field, you'd 
probably want to specify SI units (there are *lots* of them :-)

///Peter
-- 
XML FAQ: http://xml.silmaril.ie/