So you got this with the project I hosted on : it is a flag named after the name of the module of code (here the name of the UE4 project, ProceduralMesh). It tell the Unreal Build Tool or the compiler to export those symbols as a public API for other modules of your project.
So if you import the sample code into one of your project that you named otherwise, you have to Rename the flag accordingly.
You can also remove it altogether if you don’t need multiple game modules.
Cheers!