Switch -ONI - allow potentially incompatible names
While NTFS file system permits file names with trailing spaces and dots, also as reserved device names, a lot of Windows programs fail to process such names correctly. If this switch is not specified, WinRAR removes trailing spaces and dots, if any, from file names when extracting. It also inserts the underscore character in the beginning of reserved device names, such as aux.
Specify this switch if you need to extract such names as is. It might be associated with compatibility or even security risks.
Switch -oni is the command line equivalent of "Allow potentially incompatible names" option in extraction dialog.