Visual Studio project type(s).
Can be set to one or more UUIDs recognized by Visual Studio to indicate the type of project. This value is copied verbatim into the generated project file. Example for a managed C++ unit testing project:
{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}
UUIDs are semicolon-delimited.