[tei-council] MD chapter revised: namespace rules

[Lou Burnard]

Dan O'Donnell wrote:

> Finally a question: what happens if I extend a tei attribute to a new
> element (or make it global).
> 

That's an unclean modification -- the set of documents matched by the 
extended schema is not a pure subset of the set of documents matched by 
the unextended one -- ergo you must put a namespace on something, 
presumably  the attribute you've now defined as global.