| SYSTEM | |
| ------ | |
| .. versionadded:: 3.25 | |
| This directory property is used to initialize the :prop_tgt:`SYSTEM` | |
| target property for non-imported targets created in that directory. | |
| It is set to true by :command:`add_subdirectory` and | |
| :command:`FetchContent_Declare` when the ``SYSTEM`` option is given | |
| as an argument to those commands. |