+Here is a minimalistic platform example, describing a zone in which routing is fully described, containing two hosts and a
+link. You need to explicitly add a :ref:`pf_tag_route` between ``host0`` and ``host1`` for this link to get used during
+communications.
+
+.. code-block:: xml
+
+ <zone id="AS5-4" routing="Full">
+ <host id="host0" speed="1Gf"/>
+ <host id="host1" speed="2Gf"/>
+ <link id="link0" bandwidth="125MBps" latency="100us"/>
+ <route src="host0" dst="host1"><link_ctn id="link0"/></route>
+ </zone>
+
+SimGrid only performs minimalistic verifications about the described platforms, to make things flexible and interesting.
+It enables weird topologies, such as a single link used for all communications in a large platform, or a link used by
+hosts from different zones, or even worse. It is also OK to not describe some routing paths. SimGrid won't complain
+unless your application tries to actually use inexistant paths. In short, it is your responsibility to write proper
+platform files, and SimGrid will not try to be smarter than you!
+
+To learn further about platform descriptions, the easiest is to look at the