This property indicates whether the virtual directory should use the default hypertext transfer protocol (HTTP) error messages or custom HTTP error messages. When you create a new virtual directory, the value for this property is (Default Error Mappings). This indicates that all of the HTTP error codes are mapped to the default HTTP error messages.

If any custom error messages are configured for one or more HTTP errors, the value for this property is (Customized Error Mappings). To configure custom error messages for one or more HTTP errors, click the ellipsis button (...) to open the Custom Errors dialog box.