-Your platform description should follow the specification presented in
-the `simgrid.dtd <https://simgrid.org/simgrid.dtd>`_
-DTD file. The same DTD is used for both the platform and deployment
-files.
+Your platform description should follow the specification presented in the
+`simgrid.dtd <https://simgrid.org/simgrid.dtd>`_ DTD file. The same DTD is used for both platform and deployment files.
+
+.. _pf_tag_config:
+
+------------------------------------------------------------------
+<config>
+------------------------------------------------------------------
+
+Adding configuration flags directly into the platform file becomes particularly useful when the realism of the described
+platform depends on some specific flags. For example, this could help you to finely tune SMPI. Almost all
+:ref:`command-line configuration items <options_list>` can be configured this way.
+
+Each configuration flag is described as a :ref:`pf_tag_prop` whose 'id' is the name of the flag and 'value' is what it
+has to be set to.
+
+**Parent tags:** :ref:`pf_tag_platform` (must appear before any other tags) |br|
+**Children tags:** :ref:`pf_tag_prop` |br|
+**Attributes:** none
+
+.. code-block:: xml
+
+ <?xml version = '1.0'?>
+ <!DOCTYPE platform SYSTEM "https://simgrid.org/simgrid.dtd">
+ <platform version = "4.1">
+ <config>
+ <prop id = "maxmin/precision" value = "0.000010" />
+ <prop id = "cpu/optim" value = "TI" />
+ <prop id = "network/model" value = "SMPI" />
+ <prop id = "smpi/bw-factor" value = "65472:0.940694;15424:0.697866;9376:0.58729" />
+ </config>
+
+ <!-- The rest of your platform -->
+ </platform>