diff --git a/README.md b/README.md
index 5a6625e..fc6cc69 100644
--- a/README.md
+++ b/README.md
@@ -58,12 +58,22 @@ That's all. Snapcontrol will now be called by the Windows scheduler. See "snapco
 
 ```dos
 C:\>snapcontrol.exe /?
-usage: snapcontrol.exe [ /S | /I | /V> | /D | /? ]
+usage: snapcontrol.exe [ /S | /I | /V | /D | /? ]
     /S = silent mode (no user interaction!)
     /I = install/update scheduler job
     /V = show version
     /D = dry run
     /? = help
+
+RETURNCODES:
+-----------------------------------------------------
+99 = usage was called / wrong arguments or parameters
+98 = cannot read inifile (does not exist ?)
+97 = i don't have admin rights
+96 = mailer (cmail) not found or not working
+95 = Drive Snapshot version is not supported
+94 = Drive Snapshot exe not found
+ 0 = OK
 ```
 
 *HINT:* Everytime you change the values in "BackupSched" or "BackupStart" you will have to call snapcontrol.exe with the /I switch.