This parameter specifies the value of ⎕WX in a clear workspace. This in turn determines whether or not the names of properties, methods and events of GUI objects are exposed. If set (⎕WX is 1), you may query/set properties and invoke methods directly as if they were variables and functions respectively. As a consequence, these names may not be used for global variables in GUI objects.

See also Expose properties of GUI Namespaces and ⎕WX.