Microsoft MS-DOS had reserved these names for these system device drivers.
CON : Keyboard and displayPRN : System list device, usually a parallel portAUX : Auxiliary device, usually a serial portCLOCK$ : System real-time clockNUL: Bit-bucket deviceA:-Z: : Drive lettersCOM1 : First serial communications portLPT1 : First parallel printer portLPT2 : Second parallel printer portLPT3 : Third parallel printer portCOM2 : Second serial communications portCOM3 : Third serial communications portCOM4 : Fourth serial communications port
Try to create a file or folder with these names on your Windows desktop and see what happens.
Even today if you try to name a folder using one of these reserved names, you will receive the following error message: The specified device name is invalid. These restrictions still exist in the NT-based Windows, possibly the reason being to allow compatibility for running 16-bit programs and for command-line based programs. The complete Windows Naming Files, Paths, Namespaces, Conventions can be found here.
Create CON, AUX, NUL folder and files with a click in Windows
While you can use Linux or MS-DOS commands to create the folder names such as “con”, I came across this app Concu which claims to let you create and delete folders with restricted names, in a click. It’s a CNET link so remember to click on the Direct Download Link.
Why does this program exist? Just to make a point that it can be done using a tool, that’s all! I know, I know this is real old stuff, but this is for those who may not be knowing about it. ;)
