The VDS_PARTITION_FLAG enumeration defines flags that describe partitions. A value that accepts these flags MUST have the following flag set or MUST have the value set to 0 if the flag is not applicable to a given partition.

 typedef enum _VDS_PARTITION_FLAG
 {
   VDS_PTF_SYSTEM = 0x00000001
 } VDS_PARTITION_FLAG;

VDS_PTF_SYSTEM:  Value that indicates that the partition is a system partition.