File Names

Under the FAT file system, the filename consists of a base name of 1 to 8 
characters plus an optional extension composed of a period plus 1 to 3 
more characters. 

You can use alphabetic and numeric characters plus the punctuation marks ! 
# $ % & ' ( ) - @ ^ _ ` { } and ˜ in both the base name and the extension 
of a FAT filename.  Because the exclamation point [!], percent sign [%], 
caret [^], at sign [@], parentheses [()], and back-quote [`] also have 
other meanings to CMD.EXE, it is best to avoid using them in filenames. 

The HPFS file system allows file names with a maximum of 255 characters, 
including spaces and other characters that are not allowed in a FAT system 
file name, but excluding some punctuation characters which are allowed in 
FAT file names.  See your operating system documentation for details on 
the characters allowed.  If you use file names which contain semicolons 
[;], see Wildcards for details on avoiding problems with interpretation of 
those file names under CMD.EXE. 

HPFS file names are stored and displayed exactly as you entered them, and 
are not automatically shifted to upper or lower case.  For example, you 
could create a file called MYFILE, myfile, or MyFile, and each name would 
be stored in the directory just as you entered it.  However, case is 
ignored when looking for filenames, so you cannot have two files whose 
names differ only in case (i.e., the three names given above would all 
refer to the same file).  This behavior is sometimes described as 
"case-retentive but not case-sensitive" because the case information is 
retained, but does not affect access to the files. 

Files stored on HPFS volumes often have "FAT-compatible" names:  names 
which contain only those characters legal on a FAT volume, and which meet 
the 8-character name / 3-character extension limits.  Programs which 
cannot handle long names generally can access files by using 
FAT-compatible names. 

If an HPFS-compatible file name includes spaces or other characters that 
would not be allowed in a FAT name, you must place double quotes around 
the name.  For example, suppose you have a file named LET3 on a FAT 
volume, and you want to copy it to the LETTERS directory on drive F:, an 
HPFS partition, and give it the name Letter To Sara.  To do so, use either 
of these commands: 

        [c:\wp] copy let3 f:\LETTERS\"Letter To Sara"

        [c:\wp] copy let3 "f:\LETTERS\Letter To Sara"

The HPFS file systems do not explicitly define an "extension" for file 
names which are not FAT-compatible.  However, by convention, all 
characters after the last period in the file name are treated as the 
extension.  For example, the file name "Letter to Sara" has no extension, 
whereas the name "Letter.to.Sara" has the extension Sara. 

Additional information about disk files and file systems is available 
under Drives and Volumes, File Systems, Directories and Subdirectories, 
and File Attributes and Time Stamps.