The DefaultValidationMessages property is used to access the default validation error messages. Customized messages can be associated with individual validation criteria (see Customizing Error Messages), but when no customized messages are specified for a given criterion, the appropriate default message is used. Note: Custom error messages are accessed through the CustomValidationMessages property of a validation criterion. 

The ValidationProvider component also has properties that allow developers to customize how validation errors are signalled. The icon used to signal that an input component's value is invalid can be specified using the Icon property. 

Input Validator for WinForms also provides the following properties: ValidationExpression, IconPadding and IconAlignment.