Infringements to the civilian and humanitarian character of sites and settlements result in major protection concerns for internally displaced people and refugees hosted in the sites. The Aide-Mémoire resulted from consultations initiated by the ICRC and UNHCR, with valuable input from the UN Department of Peacekeeping Operations (DPKO). The first part of the Aide-Mémoire sets out the necessary context and principles with regard to the civilian and humanitarian character of sites. It provides a description of the main operational challenges and dilemmas that humanitarian actors confront and examines the content of applicable legal frameworks. The second part offers measures for humanitarian actors to consider when working toward maintaining the civilian and humanitarian character of sites. These measures include efforts to engage actors beyond the humanitarian community, recognizing that an effective interplay with security and political actors is fundamental in achieving protection outcomes.