Universal Negotiation Primitives
OK
, OK (2 types)
PROP
, proposal
RFD
, request for data
RFP
, request for proposal
RFT
, request for text of proposal
TXD
, transmit data (either direction)
SRY
, (sorry) refusal with reason (4 types)
STP
, stop negotiation
Jim Miller
http://www.w3.org/