94 …. Military occupation is considered to exist in a territory, or part of a territory, if the following elements can be demonstrated: the presence of foreign troops, which are in a position to exercise effective control without the consent of the sovereign. According to widespread expert opinion physical presence of foreign troops is a sine qua non requirement of occupation], i.e. occupation is not conceivable without “boots on the ground” therefore forces exercising naval or air control through a naval or air blockade do not suffice.
As also the next paragraph which could be relevant to Gaza, perhaps also Area A of in Judea and Samaria:
95. The rules of international humanitarian law do not explicitly address the issue of preventing access to homes or property. However, Article 49 of Convention [No. IV] relative to the Protection of Civilian Persons in Time of War of 12 August 1949 (“the Fourth Geneva Convention”) regulates issues of forced displacement in or from occupied territories. [emphasis added]
As JT noted, this is support for view that art 49(6) does not apply to voluntary settlement.