When RunAsService is set to 1 or 2 (the default is 0) Dyalog APL will not prompt for confirmation when the user logs off, and the interpreter will continue to run across the logoff /logon process. The value 2 reduces the resources used by a Dyalog service by disabling the graphical user-interface features. In this mode, ⎕WC object will fail with a LIMIT ERROR unles the object is Timer, which is the only one that remains enabled.