[relax-ng-comment] Regular expressions?

["J. David Eisenberg" <catcode@catcode.com>]

I am going to be teaching an XML course at a local college this spring. To
keep my students' heads from exploding, I have decided to teach Relax NG
instead of XML Schema.

I need to know how to specify a regular expression as a datatype for an 
element content or attribute value.  I'll be using jing as a validator, 
and it appears to have a regex parser in it.

(I also need this to validate an XML data file that I maintain; one of its 
attribute values must be built from the letters KCJOW - in that order; the 
Perl pattern would be m/K?C?J?O?W?/)

Apologies if this has been asked 10**5 times before; I didn't find 
anything in a quick search of archives.

-- 
J. David Eisenberg  http://catcode.com/