Why can't I name a project "Con" in Visual Studio?

In Visual Studio I started making a new project named "Config", and I noticed some red text show up after a few letters.

Why? Is Con a reserved word somewhere? It looks like I can make projects named int or const.

>Solution :

Con is a reserved keyword for Windows. Try to create a con folder or file, and Windows will refuse it

See https://answers.microsoft.com/en-us/windows/forum/all/why-cant-i-create-a-folder-with-con-name/23c86662-4988-4c7d-9c2d-3e33d4413de3