* Aryeh Gregor Simetrical+wikilist@gmail.com [Fri, 18 Jun 2010 15:40:54 -0400]: ....
Oh, I see. That's really terrible, then, and we should avoid presentational tables if at all possible. I think this really has to be done on the content side, though, not on the software side -- auto-translating tables to divs sounds like a bad idea.
Maybe we could remove attributes like cellpadding, cellspacing, align, etc. from the attribute whitelist. That would make it much harder to use presentational tables, wouldn't hurt non-presentational table use much, and would also improve our standards conformance (HTML5 bans them). We'd have to announce this way in advance and give people tools to adapt content before we break everything, but it'd be doable if we really wanted.
Maybe it would be better to introduce non-standard (user-defined) attribute of element (tag), to indicate the type of table ("real table" or "layout table"), instead of breaking existing code? Then, screen readers could easily pick the value of table element attribute to guess whether column number and / or column header should be repeated or not. I haven't looked what HTML5 specification says about validation of user-defined attributes, though. Dmitriy