ARIA: table role - Accessibility
if the table contains sortable columns or rows, the aria-sort attribute should be added on the header cell element (not the table itself).
...for sortable columns, see the columnheader aria role.
...the columns are sortable, but not currently sorted, as indicated by the aria-sort property on the column headers.

ARIA: row role - Accessibility
for sortable columns, see the columnheader aria role.
...the columns are sortable, but not currently sorted, as indicated by the aria-sort property.

HTMLTableElement - Web APIs
living standard added the sortable property and the stopsorting() method.

ARIA: rowgroup role - Accessibility
the columns are sortable, but not currently sorted, as indicated by the aria-sort property.

overview - Accessibility
accordingly to wcag 2.0 and aria tab panel example here on codetalks lightbox wcag 2.0 and aria-conformant lightbox application http://majx-js.digissime.net/js/popin/ form validation wcag 2.0 and aria-conformant live form validation tables german tutorial on creating an accessible form simple grid example at codetalks date picker grid at codetalks wcag 2.0 and aria-conformant sortable tables ...