This note provides guidance on using the IASC Gender Marker to design humanitarian projects to respond to the distinct needs and interests of women, girls, boys, and men by (1) integrating gender issues in their response plans; (2) building the capacity of cluster partners to design projects that better meet the needs of women, girls, boys, and men; (3) using a gender code in routine record-keeping to allow the tracking of gender-related investments in each cluster; and (4) monitoring implementation to ensure that women, girls, boys, and men participate and benefit according to the project design.