File name conventions are the rules used to form file names in a given file system. Although each installable file system (IFS) can have specific rules about how individual components in a directory or file name are formed, all file systems follow the same general conventions for combining components. For example, although the FAT file system requires that file and directory names have the 8.3 file name format, and HPFS supports names of up to 255 characters long, both file systems use the backslash (\) character to separate directory names and the file name when forming a path.

When creating names for directories and files, or when processing names supplied by the user, an application must follow these general rules:

• Process a path as a NULL-terminated string. An application can determine maximum length for a path by using DosQuerySysInfo.

• Use any character in the current code page for a name, but do not use a path separator, a character in the range 0 through 31, or any character explicitly prohibited by the file system.

  The following characters are reserved by the operating system. Do not use them in directory or file names.

      <   >   :   "   /   \   |
  

  Although a name can contain characters in the extended character set (128 - 255), an application must be able to switch code pages if necessary to access the corresponding file.

• Compare names without regard to case. Names such as "ABC", "Abc", and "abc" are considered to be the same.

• Use the backslash (\) or the forward slash (/) to separate components in a path. No other character is accepted as a path separator.

• Use the dot (.) as a directory component in a path to represent the current directory.

• Use two dots (..) as a directory component in a path to represent the parent of the current directory.

• Use a period (.) to separate components in a directory name or file name. Unless explicitly defined by a file system, no restrictions are placed on the number of components in a name.