7. A non-transitory computer readable medium including program code for providing a message-based interface for exchanging information for a request to create or update an export declaration using customs-relevant business transactions, the medium comprising: program code for receiving via a message-based interface derived from a common business object model, where the common business object model includes business objects having relationships that enable derivation of message-based interfaces and message packages, the message-based interface exposing at least one service as defined in a service registry and from a heterogeneous application executing in an environment of computer systems providing message-based services, a first message for a request for an export declaration request that includes a first message package derived from the common business object model and hierarchically organized in memory as: an export declaration request request message entity; and an export declaration request package comprising an export declaration request entity, where the export declaration request entity includes a reconciliation period counter value, an item list complete transmission indicator, a base business transaction document type code, an export declaration block indicator, and an export declaration cancel indicator; program code for processing the first message according to the hierarchical organization of the first message package, where processing the first message includes unpacking the first message package based on the common business object model; and program code for sending a second message to the heterogeneous application responsive to the first message, where the second message includes a second message package derived from the common business object model to provide consistent semantics with the first message package.
9. The computer readable medium of claim 7 , wherein the export declaration request entity comprises at least one of the following: an incoterms, a transport mode code, a transport means, a total net weight quantity, a total net weight quantity type code, a total gross weight quantity, and a total gross weight quantity type code.