The Humanitarian Overseas Service Medal is an award in the Australian honours system. The award is presented to those who perform humanitarian service in a foreign country, in particular those working in dangerous environments or conditions or during a humanitarian crisis. The award was introduced by letters patent on 16 April 1999, following a review of the Australian honours and awards system beginning in 1995. Potential recipients have to prove they worked for a minimum of 30 days in the location depicted by the clasp, during a period of time set in the award criteria. In addition, potential recipients have to be working for an aid organisation recognised by the criteria or with a United Nations taskforce during that timeframe. In 2005, special criteria were established for people working during the 2004 Indian Ocean earthquake or the 2005 Nias–Simeulue earthquake, with a maximum time period of 7 or 14 days depending on the time frame. The medal was originally intended as a civilian award, in parallel with the Australian Service Medal and the Police Overseas Service Medal, and until 2005 the Australian Defence Force had never been declared an eligible organisation. This is because, in most cases, the Australian Service Medal is already available to military personnel serving alongside humanitarian relief operations. However, defence personnel on leave of absence and serving an eligible organisation could qualify for the medal. The declaration of eligible organisations for the Indian Ocean clasp was the first time the Australian Defence Force was declared an eligible organisation, as Operation Sumatra Assist was purely a disaster relief operation and did not attract any military operational service award. The Australian Defence Force was again declared an eligible organisation for the participation of its personnel in Operation Pakistan Assist, part of the Australian humanitarian response to 8 October 2005 Pakistan earthquake. However, the medal has not been awarded to Defence personnel assigned to Operation Tsunami Assist who both lived through both Tsunami's and were forced assisgned in Penang Malaysia. Elements include 324 Combat Support Squadron (and operational augmentees) and Rifle Company Butterworth. All attempts by ADF members to be recognised for their service in Operation Tsunami Assist whilst serving in Malaysia (including those injured or who lost family during both Tsunami's) have been rejected by Prime Minister and Cabinet for the HOSM and by the Department of Defence for the Australian Service Medal.