Doc patches

docs/manual/Migration Guides/index.md

@@ -3,7 +3,7 @@
 Sometimes we can not guarantee automatic updating between new versions of our Apps.
 These pages include some common scenario's and give some guidance how to manually move between different versions and Trains.
 
-##### Between Trains
+### Between Trains
 
 An app will always be just in one train. If an App moves to a different train, you will not be able to update automatically
 Our basic guidence for these cases is:
@@ -17,7 +17,17 @@ Our basic guidence for these cases is:
 - Put back all your old files.
 - Re start the new App
 
-##### Between Versions
+### Between Versions
 
 When new versions introduce breaking changes (which would often be major version changes) they might(!) require the user to reinstall.
 However: We often already provide migration scrips and dealth with these issues manually.
+
+##### Common 2.0 -> common 3.0 based Apps
+
+In cases you upgrade to a common 3.0 based app, reinstall is currently required. Please be aware: Installing will nuke your data!
+Be also aware that we do not have common 2.0 based installs available in the version dropdown
+
+##### Common 3.0 -> common 4.0 based Apps
+
+In cases you upgrade to a common 4.0 based app, reinstall is currently required. Please be aware: Installing will nuke your data!
+However: Common 3.0 based Apps are still available to be installed using the version dropdown