Have you tried creating a folder named CON?Try it. You wont be able to have a folder with such a name.

CON is described as console. It is hardware name in DOS and windows operating systems. In DOS and windows operating system some hardware specific name can not be used as file name or folder names. The CON is referred to the combination of Key board and Monitor and is called Console. We can use the CON to create the text files.

CON is not the only name, which is not supported. There some other keywords that can’t be used as file name or the folder name. They are NUL, PRN, AUX, CLOCK$, COM0, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT0, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9.All the above mentioned are the computer parts name. For example PRN refers as Printer, COM refers to communication ports.

Apart from these reserved keywords, some special characters are also forbidden as filer name or the folder name. / \ : * ? " < > | are not allowed as part of the file name or the folder name. Whenever we will try to include theses characters in our file name or the folder name, we will get a warning message. We must follow these rules while naming the file, otherwise we can not save the data in file.

Another cool one. TRY THIS:

create a new notepad file, empty.
just write "bush hid the facts" without quotes and save it, dont press enter.

see what happens :D