Internal displacement is not a new phenomenon, yet it has come to the fore in recent years capturing significant and sustained international attention and concern. However, despite being firmly embedded in the international lexicon, there is no universal or legal definition of an Internally Displaced Persons (IDPs) though several definitions have been offered. The list of causes of displacement is not exhaustive, as highlighted by the words ‘in particular’. An important distinction with the ‘refugee’ concept is that not all situations of internal displacement will necessarily be of concern to the international community. The Guiding Principles approach displacement from the perspective of the needs of internally displaced persons. These needs have been described in mission reports prepared by the representative of the Secretary-General, Francis M. Deng, and in other relevant studies and discussions with experts.