the Nomination File. A request for a minor boundary change, one that does not have a significant impact on the extent of the property or affect its "outstanding universal value", is also evaluated by the advisory bodies before being sent to the committee. Such proposals can be rejected by either the advisory bodies or the Committee if they judge it to be a significant change instead of a minor one. Proposals to change a site's official name are sent directly to the committee. Endangerment A site may be added to the List of World Heritage in Danger if conditions threaten the characteristics for which the landmark or area was inscribed on the World Heritage List. Such problems may involve armed conflict and war, natural disasters, pollution, poaching, or uncontrolled urbanisation or human development. This danger list is intended to increase international awareness of the threats and to encourage counteractive measures. Threats to a site can be either proven imminent threats or potential dangers that could have adverse effects on a site. The state of conservation for each site on the danger list is reviewed yearly; after this, the Committee may request additional measures, delete the property from the list if the threats have ceased or consider deletion from both the List of World Heritage in Danger and the World Heritage List. Only three sites have ever been delisted: the Arabian Oryx Sanctuary in Oman, the Dresden Elbe Valley in Germany, and the Liverpool Maritime Mercantile City in the United Kingdom. The Arabian Oryx Sanctuary was directly delisted in 2007, instead of first being put on the danger list, after the Omani government decided to reduce the protected area's size by 90 per cent. The Dresden Elbe Valley was first placed on the danger list in 2006 when the World Heritage Committee decided that plans to construct the Waldschlösschen Bridge would significantly alter the valley's landscape. In response, Dresden City Council attempted to stop the bridge's construction. However, after several court decisions allowed the building of the bridge to proceed, the valley was removed from the World Heritage List in 2009. Liverpool's World Heritage status was revoked in July 2021, following developments (Liverpool Waters and Bramley-Moore Dock Stadium) on the northern docks of the World Heritage site leading to the "irreversible loss of attributes" on the site. The first global assessment to quantitatively measure threats to Natural World Heritage Sites found