This indicates the storage type of this row. Like cpwVcEnetStorageType but scoped to an individual priority-mapping entry, this determines whether that specific COS-mapping row persists across a reboot independently of whatever storage type was chosen for the parent VC row itself. For example, an admin could configure the main VC row as nonVolatile while leaving a temporary, test-only priority mapping row set to volatile, so only that specific mapping disappears on the next reload while the core pseudowire configuration survives.