The Genocide Convention needed twenty ratifications to come into force, and its drafters kept cultural genocide out of the definition
Background
The Convention on the Prevention and Punishment of the Crime of Genocide was adopted by the United Nations General Assembly at Paris on 9 December 1948. It entered into force on 12 January 1951, once the twenty ratifications required by article XIII had been obtained. The term genocide was first used by Raphael Lemkin in his book Axis Rule in Occupied Europe, published in late 1944. General Assembly resolution 96 (I) affirmed that genocide is a crime under international law and mandated the preparation of a draft convention. Drafting ran in three stages: a Secretariat text, a reworking by an ad hoc committee, and negotiation in the Sixth Committee of the General Assembly, which agreed the final text. The Secretariat's experts had divided genocide into physical, biological and cultural genocide, but the Sixth Committee voted to exclude cultural genocide from the Convention. One exception was kept: the forcible transfer of children from one group to another remains a punishable act.
In plain words
Sixth Committee Sixth Committee of the United Nations General Assembly — The General Assembly's committee that handles legal questions, including treaty texts.