RE: TT and subtitling

See inline.

	-----Original Message-----
	From: Johnb@screen.subtitling.com [mailto:Johnb@screen.subtitling.com] 
	Sent: Wednesday, February 05, 2003 2:36 AM
	To: Glenn A. Adams
	Cc: public-tt@w3.org
	Subject: RE: TT and subtitling
	
	

	Glenn A. Adams wrote: 
	>So, your position is that *no* semantic markup vocabulary 
	>should be defined by this effort? 

	I would prefer to state my position :-) as 

	"semantic markup vocabulary should be avoided where possible"  

	Is your concern that (1) all useful semantic markup can't be
	predefined; or (2) no semantic markup should be defined.  If
	it is the former, then that can be dealt with readily by proper
	use of namespaces and schema validation.

	My present view is that if there are a small number of
	common semantic attributions that can be defined and that
	support existing usage, then we should consider their inclusion.

	One way we may handle your desire to have something specify
	*only* the timing aspects is to produce our results in a modular
	form, so that for those applications that only want timing, then
	they could make use of only the module that defines it (along
	with any prerequisite framework module).

	It may be necessary to include markup that has semantic implications, for example hidden text that provides definitions of terms, expansions of acronyms etc. 

	The M.D.<hidden-hover>Managing Director<\hidden-hover> of Blah corporation today....  

	This is stylistic mark, not semantics markup). 

	Such a tag would have a meaning to the viewer implementation yet is also in effect converying semantic information about the text it encompases. So I tend towards a more mechanistic view - that the tags should represent mechanisms involved in TT delivery and display (but not STYLE :-) - not the semantic of the text itself. So TT should perhaps support layers of text presentation - yet not in a way that implies what those layers are for.....