The Inter-Agency Standing Committee (IASC) published the original Women, Girls, Boys and Men. Different Needs - Equal Opportunities: Gender Handbook in Humanitarian Action (2006). The purpose of the handbook was to provide humanitarian actors with guidance on gender analysis, planning and actions to ensure that the needs, priorities and capacities of women, girls, men and boys are considered in all aspects of humanitarian response. The first edition predated the more recent humanitarian reform and Transformative Agenda processes and as such, did not reflect the current iteration of the sector system, the IASC Gender Marker, the Humanitarian Programme Cycle and other advances in humanitarian coordination, leadership, accountability and partnership. After wide consultations with IASC members, sector leaders, field users and donors, the Gender Handbook has been updated. The revised version is a concise guide built upon lessons learned by the humanitarian community and reflects the main challenges faced in ensuring that gender is adequately integrated into humanitarian planning and programming. The handbook is complemented by detailed information found in the regularly updated online platform. The review of the handbook was undertaken by the IASC Gender Reference Group in 2016. It was endorsed by the IASC to meet collective commitments on gender equality in humanitarian action.