The icon is in the solution explorer next to one of the generated classes
This icon indicates that it is a generated file. See Visual Studio Image Library for more information.
These are files (especially the .resx resource file) that are automatically generated by the designer, for example, when developing a form with two languages โโ(localizable: true), VS automatically generates resource files while you go through ... https://msdn.microsoft .com / en-us / library / y99d1cd3 (v = vs. 100) .aspx