Reference number: CH000043 How to create file extensions longer than three characters.
Question:
How to create file extensions longer than three characters.
Answer:
Microsoft DOS, Windows 3.x, Windows 95, Windows 98, and Windows NT These versions of Microsoft Windows do not support file extensions longer than three characters. Microsoft Windows 2000, Windows ME, Windows XP These versions of Microsoft Windows do support file extensions that are longer than three characters. However, it is important to realize that the majority of all Microsoft programs that rely on file extensions commonly only utilize three character file extensions. BSD, all Apple Macintosh Operation systems, Linux, OS/2 Warp, Unix, and variants of each of the these operating systems Each of these operating systems support the availability of a longer than three character file extension, although some of these operating systems do not utilize file extensions. While it is possible to create a file extension longer than three characters in these operating systems, the
programs used to open the files must also support long file extensions. | 
