a file name can contain any type of character, it can be start from any character,number& can start with symbol also.
260 characters
Windows 95 supported file names up to 255 characters in length.
Extension
The CSS-names; names of selectors, classes and IDs can contain characters a-z, A-Z, digits 0-9, period, hyphen, escaped characters, Unicode characters 161-255, as well as any Unicode character as a numeric code. The names cannot start with a dash or a digit. (Note: in HTML the value of the CLASS attribute can contain more characters).
The maximum length of a directory name or file name is affected by the location itself.The maximum length of the path to a file on a modern Operating System is 255 characters.
Stuart Little
8.3 file name i.e. <8 characters fo filename>.<3 chars for extension> But U can not use special characters in file name as \ / : * ? " < > |
Behavior
8 characters a decimal the 3 letters for extension. 8.3
"Dir ", where is comprised of some combination of letters, numbers and special characters (wildcard * or ?) (e.g. Dir myFile*.txt)
You can not use any of the following: \ / : * ? " < > |
In MS-DOS, file names can be up to eight characters long, followed by a period and up to three characters for the file extension (e.g., FILENAME.EXT). File names can contain letters, numbers, and certain special characters, but cannot contain spaces or special characters such as \ / : * ? " < > |. Additionally, file names are not case-sensitive in MS-DOS.