Strange

I accidentally found one strange thing in window OS it is not new but you can try in your machine as well.

I tried to create one folder name CON on my machine but machine not allowed me to create that folder and gave me an error as below image.
The specified device name is invalid.

So, i searched above error on the google. so what i found is interesting.
You can not use below listed folder names because it is used by Microsoft internally:

• CON
• PRN
• AUX
• COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, COM0
• LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, LPT9, LPT0

For more information:
https://social.technet.microsoft.com/Forums/exchange/en-US/e22c021d-d188-4ff2-a4dd-b5d58d979c58/the-specified-device-name-is-invalid?forum=w7itprogeneral

https://superuser.com/questions/86999/why-cant-i-name-a-folder-or-file-con-in-windows