1. A computer-readable storage medium having stored thereon a data structure described by an XML schema for receiving data formatted in accordance with a first version of the data structure and for presenting the received data in an arrangement defined by the data structure for validation by a device using a current version of the data structure, the data structure comprising: at least one optional data member described in the XML schema to render the received data functional within the current version of the data structure when optional data is absent from the received data, wherein an optional nature of the at least one optional data member is designated in the XML schema; at least one construct of a first type described in the XML schema to render the received data functional within the current version of the data structure when the received data includes an unknown data entity that is not specified by the current version of the data structure, wherein a limitation on a number of occurrences of the at least one construct of the first type and a specification of the at least one construct of the first type is defined in the XML schema; at least one construct of a second type described in the XML schema to render the received data functional within the current version of the data structure when the received data includes an optional data entity that is specified by the current version of the data structure, wherein the at least one construct of the second type tolerates an absence of the optional data entity in rendering the received data functional within the current version of the data structure, wherein a limitation on a number of occurrences of the at least one construct of the second type and a specification of the tolerance of the absence of the optional data entity of the at least one construct of the second type is defined in the XML schema; and wherein, the at least one optional data member, the at least one construct of the first type and the at least one construct of the second type of the data structure are for receiving data formatted in accordance with the first version and for presenting the received data in an arrangement defined by the data structure for validation by the device using the current version, wherein the received data comprises data received in a Service Oriented Architecture (SOA).