What is an 'anonymous' sender?

A bit of terminology discussion here…

In a recent article, Yasser introduced this following use of the word ‘anonymous’:

“An application comes to life on the network by using an Indigo port, which acts as the gateway between the application and the network. Each port is identified by a unique URI known as the port's identity role. If the application doesn't need its port to be addressed by other applications on the network (e.g., the port is used only to send messages but never to receive messages), such a port may not have an identity role, in which case it is said to be anonymous.” 

In some recent discussions on the Indigo team, this caused some confusion, because to many of us, when you say something is sent anonymously, that has a specific meaning as far as security identity.  That is, we expected it to be similar to the Windows ‘Guest’ identity or ‘Everyone’ group; the security identity of last resort.  As you can see above, though, this is another use of the term ‘anonymous’ that has not very much to do with security identity – instead it says that the sender is not addressable.  That is, even though you received something from them, you can’t send anything back; they don’t have an address to send to.  (That is, unless you happen to be lucky enough to have an HTTP response, or something similar, on which to piggy-back your information.)

What do you folks think?  Is ‘anonymous’ the right term to use here, or is there something better?