--- a/AbstractOperatingSystem.st	Sun May 20 09:20:23 2018 +0200
+++ b/AbstractOperatingSystem.st	Sun May 20 09:21:11 2018 +0200
@@ -6591,6 +6591,8 @@
 !
 
 playSound:fileName mode:modeInteger
+    "this is an obsolete interface"
+    
     self playSound:fileName
 !