The name of a file. Filenames dot and dot-dot, consisting solely of one and two period characters respectively, have special meaning. The following characteristics of filenames are operating system dependent:
The permitted characters. [ Example: Some operating systems prohibit the ASCII control characters (0x00 – 0x1F) in filenames. — end example ]
The maximum permitted length.
Filenames that are not permitted.
Filenames that have special meaning.
Case awareness and sensitivity during path resolution.
Special rules that may apply to file types other than regular files, such as directories.