188.8.131.52.9 hierarchySync Element
The hierarchySync element contains the result of the hierarchy synchronization download operation.
There MUST be exactly one folderChange element for each descendant folder of the root of the synchronization operation (that is the folder that was passed to the RopSynchronizationConfigure ROP, as specified in section 184.108.40.206.1.1) that is new or has been changed since the last synchronization. The folderChange elements for the parent folders MUST be output before any of their child folders.
The parent-child relationship is determined by comparing the PidTagSourceKey property (section 220.127.116.11.5) of a prospective parent folder and a PidTagParentSourceKey property (section 18.104.22.168.6) of a prospective child folder. The folderChange elements that have a PidTagParentSourceKey property with a zero-length value are children of the root of the synchronization operation.
For details about how servers determine the set of differences to be downloaded to clients, see section 22.214.171.124.