That final example with sugar-y (so to speak) grouped headers contradicts prior definition of "normalized table". First "normalized" example explicitly shows t

That final example with sugar-y (so to speak) grouped headers contradicts prior definition of "normalized table". First "normalized" example explicitly shows that grouping happens exclusively by using text repetition in adjacent headers. Row headers should then read Treatment, Baseline Treatment, Contraceptive, 2 weeks Treatment, Contraceptive, 12 weeks Treatment, Contraceptive, 20 weeks Treatment, Recovery phase and column headers should read Hormones, FSH [IU/L] Hormones, LH [IU/L] Hormones, Testosterone [nmol/L] Arguably, when there is single top-level header group in some axis (the "evil (0,0) cell"), it might be better used as table caption (here probably something like "Treatment - Hormones [dosage]") and then omitted in header cells. (From (HTML) accessibility perspective, all tables should better have caption element describing them.)