> As a general rule, I prefer to apply constraints at the 
> latest possible 
> point in the process. In this case, I don't want to set the 
> media type of 
> the output until I generate the output.
> 
> To trot out an old metaphor, water is just water. It's up to the 
> generator, the farmer, the water treatment plant, and others 
> to make good 
> use of the water when it gets to them. It'd be silly to 
> expect the water 
> to know the uses people intend for it.

I agree absolutely.

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