Archiving the data from the project "People on War" of the International Committee of the Red Cross: issues in documenting heterogeneous material and giving access to sensitive data. Reto Hadorn Head of the data archive at SIDOS, the Swiss Information Service and Data Archive for the Social Sciences. To mark the occasion of the 50th anniversary of the Geneva conventions, the ICRC organised a worldwide consultation with people who have experienced war in the past several decades in order to find ways to protect them better in times of armed conflict. The consultation was conducted with civilian populations and with combatants in 12 countries that have endured the modern forms of war. In the war settings, the consultation included national opinion surveys, as well as in-depth fo-cus group discussions and face-to-face interviews. In all, the ICRC project interviewed 12860 peo-ple in war-torn countries and conducted 105 focus groups and 324 in-depth interviews in following countries: Israel and Occupied Territories, Afghanistan, Bosnia-Herzegovina, Cambodia, Colombia, El Salvador, Georgia and Abkhazia, Lebanon, Nigeria, Philippines, Somalia and South Africa. Grossly sketched, the survey covers following topics: opinions and judgements about various acts and behaviours in war, the endangerment of civil populations, specifically women and children, the treatment of prisoners, necessity and possibility of better protection of non combatants, the role of international organisations in giving that protection. In addition, the consultation included national opinion surveys in four of the five permanent mem-ber countries of the UN Security Council - France, the Russian Federation, the United Kingdom and the United States - to see how the publics in these superpower countries view war. Finally, it included a survey of the public in Switzerland, the Depository State of the Geneva Conventions. The ICRC decided to deposit the data with the SIDOS data archive. The paper will present some of the main challenges data depositor and archive are confronted to: - The question of an eventually limited access to the data is central, given the sensitivity of the treated topics. The various solutions discussed with the data depositor will be reviewed. - An anonymizing policy and technique had to be elaborated in order to protect interviewed persons and persons named in the interviews. The interesting question is here: which are the limits to anonymization if you want to keep the meaning of what was said? - Given the variety of societies and cultures concerned, the careful documentation of the social, political and cultural contexts is a condition of valid interpretation of the transcripts. Which documents can effectively be collected and integrated into the documentation? - The complexity of that international research project explains the difficulties met in documenting some very concrete aspects of the research process. The ICRC is doing a great job in its attempt to compensate for the fact that the archiving takes place after the ending of the project.