I have a solution file with a bunch of projects inside it. One of the projects is a [Web Site Project](http://msdn.microsoft.com/en-us/library/dd547590(v=vs.110).aspx).
I was going to upgrade from VS2012 to VS2013, and simply opened the .sln file in VS2013.

It does *work*, but for some reason VS renames the project so that it is displayed in the solution explorer as "NormalNameForProject(1)" with the *(1)* being the strange part added. How come this?

I can look inside the actual .sln file and see that it indeed has the *(1)* added, but where does it come from and why is it added?