Required XML element with no data to populate it - it might not be a problem! Here's why ...

Hi Folks,

Suppose you are using data from System A to populate an XML instance document. An element in the instance is required (per the XSD) but there is no System A data to populate it. With regard to creating an instance from System A data, that is a problem (or minimally, a highly undesirable situation). 

Suppose the element's parent is optional, now is it a problem? 

Suppose the element's parent is required but the element's grand-parent is optional, now is it a problem?

How far up the tree should you look to find an optional ancestor?

Fascinating problem!

Comments?

/Roger