You do not have to specify this field. In this instance, a default message will be shown. To include the name of the validated editor into the default validation message as a subject, set the name field of the dxValidator object.
If you assign an empty string to the message field, the message will not be shown.
Set this field to "pattern" to define a rule that will be broken if the validated value does not match the regular expression specified by the pattern configuration option.