It's just normal VAT, the issue is that many "necessary" products don't have VAT on them, but tampons or pads do, even though they are a biological necessity.
Also, if we're talking about less common alternatives, women can use menstrual cups instead of tampons and pads.
It's like women-day-off when they're on their period. On one hand, it'd be nice and makes sense. On the other hand, that sex-based discrimination.
Meanwhile over there we got flat VAT for everything. No tampon tax issues! :) Paying extra 21% for basic food sucks though.