--- a/doc/installation.rst	Thu Feb 04 09:54:53 2021 +0100
+++ b/doc/installation.rst	Thu Feb 04 11:10:24 2021 +0100
@@ -8,6 +8,18 @@
 
    SàT PubSub is not released yet and this documentation is work in progress
 
+.. note::
+
+    /!\ Beware, if you're installing SàT Pubsub on a server already running in production,
+    it will replace your legacy Pubsub service, meaning that everything stored there won't
+    be available anymore (this includes, and is not limited to, bookmarks, encryption
+    keys, blogs, etc.).
+
+    Be sure to save everything from your legacy Pubsub service before switching to SàT
+    Pubsub.
+
+    Migration scripts are not yet available, help is welcome to write them.
+
 
 Requirements
 ------------