This attribute is similar to the DataContractFormatAttribute attribute. Both attributes can be applied to a method, class, or interface.
For more information about the XmlSerializer, see Using the XmlSerializer.
A method can have either of the two attributes applied, but not both. Any operation that has neither applied uses the attribute applied to the containing class. If the containing class does not have either attribute applied, the DataContractSerializer is used.
Applying the attribute also causes a XmlSerializerOperationBehavior to be created at runtime. The behavior allows customization at runtime of the serializer behavior.