Set to FIXED or FREE to indicate the Fortran source layout.
This property tells CMake whether the Fortran source files in a target use fixed-format or free-format. CMake will pass the corresponding format flag to the compiler. Use the source-specific Fortran_FORMAT property to change the format of a specific source file. If the variable CMAKE_Fortran_FORMAT is set when a target is created its value is used to initialize this property.