Thank you Jukka & Joe for your answers
The remaining problem is that on browsers that do not support attribute
selectors, such as IE 6 and earlier, the style sheet would make _all_ th
elements left-aligned. Thus, this might be one of (rare) cases where some
trick for hiding the first rule from such browsers might be in order. I
think it would be sufficient to use a "conditional comment"; see
http://www.quirksmode.org/css/condcom.html for the techniques.
On the other hand, then IE 6 would obey the align attributes but follow
its own defaults, centering <th> elements that lack an align attribute.
Rats. Almost all our tables have left aligned column headings, and I hoped
to make that the default so that alignment only needed specifying
On the other hand, if IE doesn't respect attribute selection, it's all a bit
pointless (the HTML is displayed by the end-user application in a browser
subcomponent which is - currently - IE).
Maybe the best solution is an XSL pass to fill in all the defaults...
IE7 information -- http://css-discuss.incutio.com/?page=IE7
List wiki/FAQ -- http://css-discuss.incutio.com/
Supported by evolt.org -- http://www.evolt.org/help_support_evolt/