xml-dev - Re: XML Schemas: Best Practices

["Roger L. Costello" <costello@mitre.org>]

Paul Spencer wrote:
> 
> I find your interpretations useful, and by publishing them here we 
> get a chance to disagree, which I am about to do:

Excellent!  That's exactly what we need!

> I established a circumstance when I want to re-use a type and 
> cannot re-use an element (both MovingFromAddress and 
> MovingToAddress being of type Address).

I think that we are saying the same thing (although I have obviously not
been very clear).  In your example you have an item - Address.  Should
the schema be designed to declare Address as an element or define it as
a type?  You argue that since Address's structure and content is
intended to be reused by other schemas then it should be defined as a
type.  That is what I meant by:

"... during the lifespan of an item, if it (the item) is to be
associated with multiple semantics then create a type definition."

Now that I relook at what I said I can see that it is not very clear. 
Can you think of a way to express the guideline that makes things
clear?  (Not just Paul, but anyone?)  How would you complete this
statement:

"Here are guidelines for when to declare an item as an element versus
when to define it as a type: <fill this in>"

/Roger