Can you explain the CMake variables Slicer_<moduleType>MODULES_DISABLED|ENABLED?

Can you explain how Slicer_QTLOADABLEMODULES_ENABLED/Slicer_QTLOADABLEMODULES_DISABLED works? If the Slicer_QTLOADABLEMODULES_ENABLED list is empty, does it enable all modules excepting those in Slicer_QTLOADABLEMODULES_DISABLED? And if one or more modules are listed in Slicer_QTLOADABLEMODULES_ENABLED are all others disabled by default?

Reading the documentation associated with the SlicerCheckModuleEnabled module should help.