Re: [xml-dev] XML Schema 1.1 Best Practice: Expressing Business Rules - Co-Locate or Separate?

> Michael has challenged us to define the term "business rule". I'll take a go at defining it:
>
>      A business rule is a local constraint.
>

Doesn't work for me.

I might have a local constraint that a particular application can only 
handle one telephone number for a customer, and to stop this application 
breaking, documents sent to this application must follow this 
constraint. That's hardly a business rule, it's a contraint imposed by 
the limitations of a component of the IT system. But it's still a 
"local" constraint in your sense of the term.

Michael Kay
Saxonica