>.
 </p>

 <p>
 The header information that is available is as follows:
 <ul>
 <li>a tag indicating the type of message
 <li>the intended recipient of the message, either as a <a href="../../../../com/ericsson/otp/erlang/OtpErlangPid.html" title="class in com.ericsson.otp.erlang"><code>pid</code></a> or as a String, but never both.
 <li>(sometimes) the sender of the message. Due to some eccentric
 characteristics of the Erlang distribution protocol, not all messages have
 information about the sending proce