Extended or unreadable characters
Filenames can either consist of up to 8 characters (for Windows 3.1 and previous) or up to 255 characters (for Windows 95). Both types of filenames must follow certain conventions. If extended or unreadable characters which violate these conventions are added by the computer, it could be the sign of a virus on the computer.
Following are the conventions for Windows 3.1 and Windows 95 filenames.
FOR WINDOWS 3.1 AND PREVIOUS: RULES FOR 8.3-COMPLIANT FILENAMES
The following criteria must be met for an 8.3-compliant file or directory name:
- The filename must be composed of all uppercase letters.
- Any combination of letters (A-Z) and/or numbers (0-9)\\ must be used.
- The following special characters may be used:
$ Dollar sign
% Percent sign
' Apostrophe
` Opening single quotation mark
- Hyphen
@ At sign
{ Left brace
} Right brace
~ Tilde
! Exclamation point
# Number sign
( Opening parenthesis
) Closing parenthesis
& Ampersand
_ Underscore
^ Caret
When a file or subdirectory is named in Windows 95, the system creates a primary filename, which can be a long filename, and an MS-DOS-compliant 8.3 alias.
If the file or subdirectory name is already 8.3 compliant, then only one directory entry is used.
FOR WINDOWS 95: USING LONG FILENAMES
A long filename is any filename that exceeds the standard DOS 11 character (8.3) format. Long filenames may use up to 255 characters. The maximum size of a long filename and path must not exceed 260 characters. It is recommended that the name not exceed 50-75 characters in case the file is moved and the pathname becomes longer. The following characters which are not legal for MS-DOS 6.22 or lower may also be used in a long filename: + . : = [ ]
Long filenames are case sensitive and are saved with the same capitalization as they are assigned.
MS-DOS automatically assigns an 11-character alias to any long filename. The alias is composed of the first 6 letters of the filename plus ~n (where 'n' represents a consecutive number if this filename is already in use) with a 3-character extension. (Example: LONGFI~1 for the first file named LongFileName and LONGFI~2 is assigned for a second file named LongFileName. An alias cannot be designated by the user. To view the MS-DOS name associated with a long filename, use the right mouse button to click the file, and then click Properties.
To view an alias of a file from the Windows 95 desktop, right-click on the file in Windows Explorer, My Computer, or the desktop and select 'Properties' from the popup menu. The alias appears in the value for MS-DOS Name on the General Property sheet.
The following are examples of valid filenames for Windows 95 applications:
MS-DOS name:
12345678.ABC
No limit on extension:
12345678.ABCDEF
Long filename:
123456789012345678901234567890123456789.ABC
Long filename and long extension:
1234567890123456789012345678901234567890.ABCDEF