Strongly agree. There is no reason I can think of not to permit nested
row- and colgroups.

Jasper

Jim Jewett wrote:
> [Also sent to www-html-editor]
> 
> It is fairly common to sort tabular data by multiple columns --
> implicitly creating nested rowgroups.
> 
> Neither colgroup nor any of the rowgroup instantiations (tbody, thead,
> tfoot) can nest.
> 
> In the past, this was needed for backwards compatibility -- colgroup
> elements were implicitly closed by the next colgroup.  In XHTML 2.0,
> all elements will have closing tags, so it is possible to distinguish
> a nested colgroup from an adjacent one.  Given this, I believe nested
> colgroups and (rowgroups) should be permitted.
> 
> -jJ