diff --git a/12.temporary_ins/05.coordinates-systems/20.cartesian-coordinates/10.main/textbook.en.md b/12.temporary_ins/05.coordinates-systems/20.cartesian-coordinates/10.main/textbook.en.md
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+---
+title: Cartésian coordinates
+published: true
+routable: false
+visible: false
+lessons:
+    - slug: cartesian-coordinates-linear
+      order: 1
+---
+
+!!!! *LESSON  UNDER  CONSTRUCTION :* <br>
+!!!! Published but invisible: does not appear in the tree structure of the m3p2.com site. This course is *under construction*, it is *not approved by the pedagogical team* at this stage. <br>
+!!!! Working document intended only for the pedagogical team.
+
+<!--MetaData : ... -->
+