--On Sunday, 02 December, 2007 00:25 +0100 "Peter J. Holzer"
This is an incompatible change in the protocol, as a client
conforming to RFC 2821 is of course perfectly correct in
sending the optional parameter while the server conforming to
RFC 821 is equally correct in rejecting it.
For some reason, this was not used for
NOOP, but an incompatible change was made in the core protocol
(which I admit I don't understand: What is the purpose of this
parameter? Why was it added at all? To reflect actual usage or
just because somebody thought it might be useful?)
My recollection is that DRUMS was trying to reflect existing
practice. While I haven't searched the archives, the odds that
this was done by accident and without discussion are very small.