The All India Muslim Personal Law Board, at its 16th session here last week, decided to push for the exemption of Muslim girls from the Child Marriage Act of 1929. The law demands that a girl must be 18 before she can be legally married. But the Muslim Law Board says the Shariat has laid down that a woman is of marriageable age as soon as she attains puberty. Newly elected president Moulana Nadvi said the board has decided to intervene in a Supreme Court case on the issue. The board also asked governor C. Rangarajan not to endorse a new state bill seeking to make registration of all marriages compulsory.