that are displayed in the "Attributes" column of Windows Explorer include: Directory (D): The entry is a subdirectory, containing file and directory entries of its own. Reparse Point (L): The file or directory has an associated re-parse point, or is a symbolic link. Offline (O): The file data is physically moved to offline storage (Remote Storage). Sparse (P): The file is a sparse file, i.e., its contents are partially empty and non-contiguous. Temporary (T): The file is used for temporary storage. In DOS, OS/2 and Windows, the attrib command in cmd.exe and command.com can be used to change and display the four traditional file attributes. File Explorer in Windows can show the seven mentioned attributes but cannot set or clear the System attribute. Windows PowerShell, which has become a component of Windows 7 and later, features two commands that can read and write attributes: Get-ItemProperty and Set-ItemProperty. To change an attribute on a file on Windows NT, the user must have appropriate file system permissions known as Write Attributes and Write Extended Attributes. Unix and POSIX In Unix and Unix-like systems, including POSIX-conforming systems, each file has a 'mode' containing 9 bit flags controlling read, write and execute permission for each of the file's owner, group and all other users (see File-system permissions §Traditional Unix permissions for more details) plus the setuid and setgid bit flags and a 'sticky' bit flag. The mode also specifies the file type (regular file, directory, or some other special kind). 4.4BSD and derivatives In 4.4BSD and 4.4BSD-Lite, files and directories (folders) accepted four attributes that could be set by the owner of the file or the superuser (the "User" attributes) and two attributes that could only be set by the superuser (the "System" attributes): (User) No-dump: When set, it indicates that the file or directory should not be saved during a backup operation. (User and System) Immutable: When set, indicates that the file or directory should not be altered. Attempts to open the file for writing, create a file within the directory, remove a file from the directory, rename a file within the directory, rename the file or directory, or remove the file or directory will fail with a permissions error. (User and System) Append-only: When set, indicates that the file should only be appended to. (User) Opaque: When set on a directory, indicates that the directory is opaque when viewed through a union