Inheritance of column attributes
> I don't think this is acceptable. CSS should specify that TD and TH
> elements inherit from both the SGML hierarchy (TABLE, THEAD|TBODY|TFOOT,
> TR) *and* from the COLGROUP and COL elements defining the column in
> which the cell occurs.
The CSS specification  addresses this issue. Short summary:
- borders between cells can be set on any table element including
COLGROUP and COL. In case of conflicts, the thickest will win.
- other properties (fonts etc.) follow normal inheritance rules, and
the only way to influence the presentation of an element is to address
the element itself or an ancestor. COL and COLGROUP are useless in
this regard, and a CLASS attribute should be used to apply a special
style to a column.
This is not what you asked for, but introducing multiple inheritance
would complicate matters. The tree structure of SGML/HTML does not
lend itself easily to tables.
While the rest of the CSS specification is stable at this point, the
notes on tables  were recently rewritten. Comments welcome.
Hakon W Lie, W3C/INRIA, Sophia-Antipolis, France