The SOAP 1.1 Binding for MTOM 1.0 specification details the necessary modifications to the W3C SOAP Message Transmission Optimization Mechanism (MTOM) and XML-binary Optimized Packaging (XOP) specifications necessary to successfully use these technologies with SOAP 1.1. The MTOM and XOP specifications were originally specified by the W3C with normative bindings for SOAP 1.2. However, they were intended to be capable of being used in a SOAP 1.1 context, but no formal binding was ever defined.