RE: [xml-dev] What does "optional" mean?

["Len Bullard" <Len.Bullard@ses-i.com>]

That answer makes some sense in the world of machine-handled
network-distributed documents.

It makes almost no sense in the world of human-originated hand-delivered
tech pubs.  In this world, the problems of options are that the machines
are not choosing.   Options are often in collision with human habits and
preferences.  In theory, the DTD circumscribes all of the valid
expressions.  In practice, it becomes a social network problem of who
decides which invalid constructs will be allowed within the boundaries,
as in our case, what to spend the 2% acceptable error points on.  The
consumer doesn't decide.

This is quite real and a reason for the high costs of XML-delivered
documentation.

len


From: Costello, Roger L. [mailto:costello@mitre.org] 

At this point I will do my best at characterizing what I think Walter
Perry would say: 

    The consumer of an XML instance document that
    has an omitted element or attribute is free to give
    whatever meaning he or she desires to that omission.

[Walter, if I have not accurately characterized your ideas please
correct me.]

/Roger