Processing a received message includes receiving a message that includes within the message a plurality of values and a plurality of context values. Each of the values is associated with a respective data element. The method includes identifying a first context value and those first data elements that are relevant to the first context value. The method includes selecting first rules that are specific for the first context value and applying the first rules to the values associated with the first data elements. The process includes identifying a second context value and those second data elements that are relevant to the second context value and omitting first data elements that are relevant to the second context value. The method includes selecting second rules that are specific to the second context value and applying the second rules to values associated with the second data elements.