empty-cells:hide;

thead 1	thead 2	thead 3
	td 2	td 2	td 3
th 2	td 5	td 6	td 7
th 3	td 9	td 10	td 11

empty-cells:show;

thead 1	thead 2	thead 3
	td 2	td 2	td 3
th 2	td 5	td 6	td 7
th 3	td 9	td 10	td 11