diff --git a/doc/PRE_UPGRADE.d/0.6.3~ynh2.md b/doc/PRE_UPGRADE.d/0.6.3~ynh2.md
new file mode 100644
index 0000000..6fbd8f4
--- /dev/null
+++ b/doc/PRE_UPGRADE.d/0.6.3~ynh2.md
@@ -0,0 +1 @@
+With this upgrade, the command `!sg` will be replaced by `!signal`. 
\ No newline at end of file