diff --git a/ChangeLog b/ChangeLog
index 06f749cbc34..54244427b81 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -176,7 +176,8 @@ Following changes may create regressions for some external modules, but were nec
 * Deprecated property ->fk_departement is now ->state_id everywhere.
 * Removed the method 4 of GETPOST (to get $_COOKIE). It was not used and not recommanded to use in Dolibarr.
 * Column llx_facture.facnumber change to llx_facture.ref
-
+* Variable $dolibarr_main_cookie_cryptkey is no more created at install (it was not used by Dolibarr). A new variable 
+  called $dolibarr_main_instance_unique_id is now generated at each installation. It will be used by some future features.
 
 ***** ChangeLog for 9.0.3 compared to 9.0.2 *****
 FIX: #11013
diff --git a/htdocs/conf/conf.php.example b/htdocs/conf/conf.php.example
index 886a6171818..72581f1c096 100644
--- a/htdocs/conf/conf.php.example
+++ b/htdocs/conf/conf.php.example
@@ -146,11 +146,20 @@ $dolibarr_main_db_character_set='utf8';
 // Database character set used to sort data (forced during database creation. value of database is then used).
 // Default value: depends on database driver
 // Examples:
-// dolibarr_main_db_collation='utf8_unicode_ci';
+// $dolibarr_main_db_collation='utf8_unicode_ci';
 //
 $dolibarr_main_db_collation='utf8_unicode_ci';
 
 
+// dolibarr_main_instance_unique_id
+// An ID that is unique for each installation.
+// Default value: randomly defined during installation
+// Examples:
+// $dolibarr_main_instance_unique_id='84b5bc91f83b56e458db71e0adac2b62';
+//
+$dolibarr_main_instance_unique_id='84b5bc91f83b56e458db71e0adac2b62';
+
+
 
 //##################
 // Login