In the CALS dtd I have , TGROUP is defined as follows:
<!ELEMENT tgroup - o (colspec*, spanspec*, thead?, tfoot?, tbody) >
The main problem in this definition is TFOOT position before TBODY in SGML
TGROUP structure... I guess a such definition comes from layout requirements:
if table's height is greater than a page then footer can be duplicated on each
page containing a part of the table using simpler rendering algorithms...
COLSPECs, SPANSPECs, recursive definition, missing elements (ENTRY,
COLSPEC, SPANSPEC) are hard to manage without a parser. I read some days
ago in this list that parsers'integration in browsers won't be realized
in a close future... Hmmmm. No comment ;-(
CALS tables are a very powerful recursive table definition even if such a
definition can make many implementors sweat several liters... Many users,
developers, implementors have CALS knowledge and a hudge number of
SGML documents already use this dtd. I see CALS tables integration into
HTML as a wise decision. I also see pure CALS without depreciation in HTML
as a major challenge and a major improvement.
Best regards from a traffic-congested Paris....
</Daniel>