Mark cmake cached variables as advanced.
mark_as_advanced([CLEAR|FORCE] VAR [VAR2 ...])
Mark the named cached variables as advanced. An advanced variable will not be displayed in any of the cmake GUIs unless the show advanced option is on. If CLEAR is the first argument advanced variables are changed back to unadvanced. If FORCE is the first argument, then the variable is made advanced. If neither FORCE nor CLEAR is specified, new values will be marked as advanced, but if the variable already has an advanced/non-advanced state, it will not be changed.
It does nothing in script mode.
https://cmake.org/cmake/help/v3.0/command/mark_as_advanced.html
