Clearly define the legitimacy of the demolished houses. Official website, Urban Construction Management Bureau, said that in daily life, the issuance and management of property right certificates on collective land in Yantai Development Zone are not standardized. Therefore, the Yantai municipal government stipulates that the aerial photos of a certain month in a certain year are used as the dividing line to determine whether the houses are legal or not, and the houses built before the aerial photos are regarded as legal, and the houses built afterwards are regarded as illegal.