diff --git a/docs/data-model.rst b/docs/data-model.rst
new file mode 100644
index 0000000..f365f9f
--- /dev/null
+++ b/docs/data-model.rst
@@ -0,0 +1,13 @@
+.. _data-model:
+
+Software Heritage data model
+============================
+
+TODO
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor
+incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis
+nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
+consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
+cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non
+proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
diff --git a/docs/index.rst b/docs/index.rst
index 8b64117..22eccfd 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -1,15 +1,20 @@
 Software Heritage - Development Documentation
 =============================================
 
 .. toctree::
    :maxdepth: 2
    :caption: Contents:
 
 
+Overview
+--------
+
+* :ref:`data-model`
+
 
 Indices and tables
 ==================
 
 * :ref:`genindex`
 * :ref:`modindex`
 * :ref:`search`