Switch -OS - save NTFS streams
This switch has meaning only for NTFS file system and allows to save alternative data streams associated with a file. It is especially important in Windows 2000, XP and newer Windows versions, which use streams to keep some file dependent information like file descriptions. If you use WinRAR to backup your NTFS disks, it is recommended to specify this switch.
Shell mode equivalent of this switch is the "Save file streams"option in the Archive name and parameters dialog.
This switch is supported only for RAR archives.