Issue 12055 Map referencing behaviors

[Robert D Anderson <robander@us.ibm.com>]

This is in reference to the proposal posted here:
http://www.oasis-open.org/committees/download.php/24910/IssueNumber12055.html

As noted at Tuesday's meeting, there has been some discussion off the list
about this item, primarily related to default behaviors. This proposal
states that the described behaviors (such as that for cascading metadata)
may change in a given specialization. For example, in the general topicref
case and in most specializations, metadata specified within the <topicref>
applies to the referenced content. This means that a processor could treat
specified metadata as if it was specified in the target topicref's.

In some cases, the topicref element may be specialized to provide meaning
about the referencing context, rather than the target. In that case it may
be possible to set metadata that should not cascade to the targets, but
should only be used to evaluate the reference itself.

As I understand it, the open question is - how should such overrides of the
default behavior be defined? If they are not defined within the DTD or
Schema, how can a tool anticipate the desired behavior? If they are defined
within the DTD or Schema, how can that be done, in a manner that
anticipates all of the overrides? If the changes are simply defined in the
element documentation, then tools will be unable to automatically
understand how to treat the elements, and they will require overrides.

Another, I believe less urgent, open question is about the terminology of
cascading versus inheritance. It has been suggested that the behaviors
described here, as well as in much of the map processing, is more properly
described as cascading rather than inheriting. The proposal here uses the
term "cascade". When this goes into the specification, it will use the same
terminology as the spec, whether that ends up being cascade or inherit.

Thanks -

Robert D Anderson
IBM Authoring Tools Development
Chief Architect, DITA Open Toolkit
(507) 253-8787, T/L 553-8787 (Good Monday & Thursday)