Triple talaq (talaq-ul-biddat), as practised in India, belongs mainly to which school of Muslim law?

Talaq-ul-biddat, the pronouncement of three talaqs at one time as an irrevocable divorce, is the disapproved form of talaq recognised by the Hanafi school of Sunni law, the school followed by most Sunni Muslims in India. The Ithna Ashari and Ismaili Shia schools do not recognise it.

The Supreme Court in Shayara Bano v. Union of India (2017) set it aside, and the Muslim Women (Protection of Rights on Marriage) Act, 2019 declares it "void and illegal" and makes it punishable.