What Does Question Mark Mean in Xcode Project Navigator?

Question

In the project navigator in Xcode, I am not sure what the ? is trying to tell me next to the file name.

Answer 1

I suddenly get one my file Unversioned (with ? mark), but it was old file.

It was .m file. Before problem occurred, I created copy of it, for making new similar class. I renamed a class and add new file to XCode.

Problem (with old file become Unversioned) was in not renamed comment string at beginning:

//
//  MyFirstClass.m

When I renamed it, problem with Unversioned file was resolved.

//
//  MySecondClass.m

Hope it'll helpful somebody.

P.S. Additionally maybe needed to remove and copy back this files.