Elements have properties. What properties must be agreed to, toachieve i

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

Hi Folks,

[Definition] Property: something owned; any tangible or intangible possession that is owned by someone.

Consider this instance document element:

<Publisher xmlns="http://www.book.org";>Wrox Press</Publisher>

The element has properties, including:

- name, which has the value "Publisher"
- namespace, which has the value "http://www.book.org";
- type, which has the value ??? (can this be determined solely by examining the instance document?)

If the element is "declared" in an XML Schema then it has additional properties, including nillable, abstract, substitution group affiliations. Here's the complete list of properties:

http://www.w3.org/TR/xmlschema11-1/#Element_Declaration_details

So, an element has multiple properties and the properties have values.

If a sender and a recipient want to interoperate, what set of properties and property values must they agree upon?

I think that the sender and recipient must agree on a unique name for the element. That is, they must agree on values for the name and namespace properties. For example, they agree to this unique name:

{http://www.book.org}Publisher

Does the sender and recipient need to agree on the value of the type property? Suppose the sender assumes the type of the element is an enumeration list ("Wrox Press", "New Riders", "friendsofed", "Norton Press") but the recipient assumes the type of the element is an unconstrained string. Can they interoperate?

Does the sender and recipient need to agree on other properties - nillable, abstract, etc?

Is interoperability a sliding scale, from limited interoperability to perfect interoperability? At what point is there meaningful interoperability?

/Roger