When creating or editing a site, you can set a list of sites in order of proximity to the new or updated site. During ad hoc replication, the system checks these sites in the order they appear in the list to determine which site the content should be retrieved from. By setting up the site proximity list, you can ensure that user requests are fulfilled as quickly as possible by using the closest site. By default, the master site is added to the end of the list, if it has not already been included in the list in another place in the order.