File and directory name restrictions on Windows

The New Technology File System (NTFS) in Windows has naming conventions for a file: a base file name and an optional extension, separated by a period.

Files downloaded from Syncplicity can use any character in the current code page for a name, including Unicode characters and characters in the extended character set (128-255). However, there are the following exceptions.

  • The following reserved characters:
    < > : " / \ | ? *
  • Integer value zero, sometimes referred to as the ASCII NUL character.
  • Characters whose integer representations are in the range 1-31.
  • Any other character the target file system does not allow.
  • Use a period as a directory component in a path to represent the current directory. For example, .\temp.txt.
  • Use two consecutive periods (..) as a directory component in a path to represent the parent of the current directory, for example ..\temp.txt. For more information, see Paths.
  • Do not use the following reserved names for the name of a file:
    CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9. Also avoid these names followed immediately by an extension; for example, NUL.txt is not recommended.
  • Do not end a file or directory name with a space or a period. Although the underlying file system may support such names, the Windows shell and user interface does not. However, you can specify a period as the first character of a name. For example, .temp.

For more information, see Naming Files, Paths, and Namespaces.

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