diff --git a/docs/2_4_common_schema.adoc b/docs/2_4_common_schema.adoc
index d7fc99c48..6cb3f43e3 100644
--- a/docs/2_4_common_schema.adoc
+++ b/docs/2_4_common_schema.adoc
@@ -992,7 +992,8 @@ A <<parameter>> with <<variability>> = <<tunable>> may be changed only in <<Even
 `= discrete`:
 
  * Model Exchange: The value of the variable may change only in <<EventMode>>.
- * Co-Simulation: The value may change at communication points and in <<EventMode>>, if supported.
+ * Co-Simulation: If <<EventMode>> is used (see <<eventModeUsed>>), the value of the variable may only change in <<EventMode>>.
+If <<EventMode>> is not used, the value may change at communication points and the FMU must detect and handle such events internally.
 During <<IntermediateUpdateMode>>, <<discrete>> variables are not allowed to change.
  * Scheduled Execution: The value may change only at communication points.