1. A method for dynamically associating type information about extensible messages in a service-oriented architecture, the method comprising: configuring a simple object access protocol (SOAP) message header associated with a SOAP message body to include message meta-data and semantic type information describing at least a portion of the content of the SOAP message body so as to enable a receiver to interpret and process the content of the SOAP message body using the meta-data and semantic type information included in the SOAP message header, thereby facilitating a dynamic exchange of semantic type information and meta-data information for open content message exchange between a sender and the receiver, wherein the dynamic exchange of semantic type information and meta-data information for open content message exchange between the sender and the receiver is implemented without changing message format of the message body.