Gender mainstreaming was established as a major global strategy for the promotion of gender equality in the Beijing Platform for Action from the Fourth United Nations World Conference on Women in Beijing in 1995. The ECOSOC agreed conclusions (1997/2) established some important overall principles for gender mainstreaming. A letter from the Secretary-General to heads of all United Nations entities (13 October 1997) provided further concrete directives. The General Assembly twenty-third special session to follow up implementation of the Beijing Platform for Action (June 2000) enhanced the mainstreaming mandate within the United Nations. More recently, the Economic and Social Council adopted a resolution (ECOSOC resolution 2001/41) on gender mainstreaming (July 2001) which calls on the Economic and Social Council to ensure that gender perspectives are taken into account in all its work, including in the work of its functional commissions, and recommends a five-year review of the implementation of the ECOSOC agreed conclusions 1997/2.