Well, I thought I had seen the lot with character coding issues: but it
seems that by quoting your text including the Omega character, the backslash
that I typed was converted to a W with an overlaid horizontal bar - at
least, that's how it appears to me. (It also put my message into a rather
odd font.)

If anyone can work out why this happened, I would be fascinated to know! I'm
using Outlook 2003 as my mail client (don't ask me why....)

Regards,

Michael Kay
http://www.saxonica.com/
http://twitter.com/michaelhkay 

> 
> It seems you are using "UTF" to mean an "unusual" character, 
> in some sense of the word.
> 
> Try:
> 
> <xsl:if test="matches(text(), '\P{IsBasicLatin}')">
> 
> However, it would be nice to know what you want to do 
> differently if this condition is true. If we knew, we might 
> be able to suggest a better approach.
> 
> Regards,
> 
> Michael Kay
> http://www.saxonica.com/
> http://twitter.com/michaelhkay