Blue arrow overlay on Visual Studio 2012 project files

Question

There are little blue arrows appearing on some of the files in my project in Visual Studio 2012 and I am not sure what they mean. And if I create a new class it does not have the icon on it.

Here's a screenshot: http://imgur.com/2FlGLeN

Answer 1

It indicates that the source file is not stored in the project directory. You get it with, for example, Project + Add Existing Item, select a file in another directory, click the arrow on the Add button and select "Add as Link".