Postel's Law states that you should be liberal in what you accept and conservative in what you send. This is sage advice for service development. Unfortunately, the default behavior of some deserializers breaks this advice by throwing an exception when an unexpected field is provided by a consumer. This is unfortunate, as it could simply be the consumer passing additional diagnostics over the wire with no expectation of consumption, or it could be the consumer preparing for a future update of the producer, passing a new field before the producer is prepared to deal with it. It could be the producer adding a new field to a response body which the consumer is free to ignore. None of these situation warrants an exception.

Taken from an interesting article from Brandon Byars on Enterprise Integration using REST.