+ .. example-tab:: examples/cpp/trace-process-migration/s4u-trace-process-migration.cpp
+
+..
+ TODO: These tracing examples should be integrated in the examples to not
+ duplicate the C++ files. A full command line to see the result in the right
+ tool (vite/FrameSoc) should be given along with some screenshots.
+
+Tracing user variables
+----------------------
+
+You can also attach your own variables to any resource described in the platform
+file. The following examples illustrate this feature. They have to be run with
+the following options: ``--cfg=tracing:yes --cfg=tracing/platform:yes``
+
+ - **Attaching variables to Hosts**
+
+ .. tabs::
+
+ .. example-tab:: examples/cpp/trace-host-user-variables/s4u-trace-host-user-variables.cpp
+
+ - **Attaching variables to Links**
+ The tricky part is that you have to know the name of the link you want to
+ enhance with a variable.
+
+ .. tabs::
+
+ .. example-tab:: examples/cpp/trace-link-user-variables/s4u-trace-link-user-variables.cpp
+
+ - **Attaching variables to network Routes**
+ It is often easier to update a given variable for all links of a given
+ network path (identified by its source and destination hosts) instead of
+ knowing the name of each specific link.
+
+ .. tabs::