The AllowOverride property gets or sets a value that indicates whether resources declared inside a location element can be overridden by child configuration files. The OverrideMode property gets or sets a value that specifies similar behavior, but does so for a specific configuration element or group, and uses one of the OverrideMode enumeration values. The OverrideMode property enables behavior to be inherited from a parent element.
You cannot programmatically set both the AllowOverride and OverrideMode property. Setting the AllowOverride property to true sets the OverrideMode property to Inherit. Setting the AllowOverride property to false sets the OverrideMode property to false.
The OverrideMode property is introduced in the .NET Framework version 3.5 Service Pack 1. For more information, see .NET Framework 3.5 Architecture.