Restricting UBL datatypes by using xsd:redefine with UDTs

["Stephen Green" <stephen_green@bristol-city.gov.uk>]

Folks,

Way back Joe was asking about restricting datatypes in UBL subsets
and using W3C XML Schema to do it, along with the subsetting of
the elements and/or their types.

At the time I couldn't see a way to do it as my understanding of
redefine was so green. I wouldn't say I understand it a lot now
but at least I found I could do the whole thing almost entirely
with use of xsd redefine and very little of substitution groups.
It turns out to be straightforward (relatively) and allows the
publication of schema files which import, include and redefine
the existing UBL files either in situ or in a local package: very
neat and quite cool. Sorry to be so slow with this. Maybe 
knowing it is quite possible will encourage others struggling
with using xsd redefine - or perhaps it's just me that's 
challenged by all this. A tutorial on redefine would be handy
maybe I'll get time to write one myself now :-)

All the best

Stephen Green