2.2.4.1.3 Synchronization List Message - Host
An outside application initiates the sync operation. This synchronization command also passes in the threshold data to the device. Examples of threshold data include play count and hour values. The device processes the request and returns a synchronization list (DRMSYNCLIST) to the Host. The license format is specified in [MS-DRM] section 2.2.2.3.
The synchronization list consists of all licenses on the device that exceed the "Threshold" and thus requires a license side-load. The host iterates through the synchronization list and side-loads the license to the device.