It is Sunday morning and phrases like "Semantic Steganography" sometimes creep into my head unheralded this time of the week. Especially before the kettle boils.
Sometimes I have moments of clarity pre-kettle-boil and I suspect this is one of them. The future of semantic markup is the tunnelling of semantics, unseen, inside harmless looking, presentation-oriented XHTML.
Here is the thing: with span and div elements, it is possible to encode any XML instance into a valid XHTML instance. It is a trivial matter to reverse the process to get the explict element-oriented XML back out.
In my mind's eye I see RESTian web services where users dereference URIs as a matter of course and see human-oriented stuff. Yet, hiding underneath as attributes in the XHTML are the semantic parasite attributes. These encode the semantic structure that process-to-process integration software feeds on.
Gee! But what about validation? All our grammer oriented validation technologies are element-type oriented not attribute-value-oriented! No problem. Do a quick XSLT transform prior to validation proper, to make the element structure explicit. Maybe, just maybe, this will be the use case that makes XML pipelining creep into common consciousness.
About time too.
[P.S. for markup geeks] This post has hidden, pre-caffiene semantics. Do "View Source" to see them. At least it had when it left my feed editor. I will be interested to see what happens to the markup when it goes into the big bad world out there.