This operation sends a string value in a header block whose semantic is to be ignored by the nodes in the message path, and string values in two "echoOk" header blocks. The message is relayed via an intermediary to the ultimate destination (configuration based static routing is used, no routing header entry is present). The target of the "Ignore" header block is a role that is supported only by the intermediary. One of the "echoOk" header blocks is targeted at role "none", the other at the ultimate destination. MustUnderstand is (implicitly) "false".