TELNET OUTPUT FORMFEED DISPOSITION OPTIONRFC655, NIC 31158 (Oct. 25, 1974)D. Crocker (UCLA-NMC)Online file: [ISI]<DCROCKER>NAOFFD.TXT              TELNET OUTPUT FORMFEED DISPOSITION OPTION1. Command name and code   NAOFFD - 13      (Negotiate About Output Formfeed Disposition)2. Command meanings   In the following, we are discussing a simplex connection, as described in    the NAOL and NAOP Telnet Options specifications.      IAC DO NAOFFD         The data sender requests or agrees to negotiate about output         formfeed disposition with the data receiver.  In the case         where agreement has been reached and in the absence of         further subnegotiations, the data receiver is assumed to be         handling output formfeeds.      IAC DON'T NAOFFD         The data sender refuses to negotiate about output formfeed         disposition with the data receiver, or demands a return to         the unnegotiated default mode.      IAC WILL NAOFFD         The data receiver requests or agrees to negotiate about         output formfeed disposition with the sender.  In the case         where agreement has been reached and in the absence of         further subnegotiations, the data receiver alone is assumed         to be handling output formfeeds.      IAC WON'T NAOFFD         The data receiver refuses to negotiate about output formfeed         disposition, or demands a return to the unnegotiated default         mode.      IAC SB NAOFFD DS <8-bit value> IAC SE         The data sender specifies, with the 8-bit value, which party         should handle formfeeds and what their disposition should be.         The code for DS is 1.      IAC SB NAOFFD DR <8-bit value> IAC SE         The data receiver specifies, with the 8-bit value, which         party should handle formfeeds and what their disposition         should be.  The code for DR is 0.3. Default   DON'T NAOFFD/WON'T NAOFFD      In the default absence of negotiations concerning which party, data       sender or data receiver, is handling output formfeeds, neither party      is required to handle formfeeds and neither party is PRohibited from       handling them; but it is appropriate if at least the data receiver       handles formfeed considerations, albeit primitively.4. Motivation for the Option   Please refer to section 4 of the NAOL and of the NAOFFD Telnet option    descriptions.5. Description of the Option   The data sender and the data receiver use the 8-bit value along with the   DS and DR SB commands as follows:      8-bit value                      Meaning                             0            Command sender suggests that he alone will handle                     formfeeds, for the connection.                           1 to 250     Command sender suggests that the other party alone 
                                            should handle formfeeds, but suggests that the                   indicated value be used.  The value is the number                     of character-times to wait or number of NULs to                       insert in the data stream before sending the next                   data character.      251          Command sender suggests that the other party alone                    handle formfeeds, but suggests that each                              occurrence of the character be replaced by                            carriage-return/line-feed.                               252          Command sender suggests that the other party alone                    handle formfeeds, but suggests that they be                           discarded.                                               253          Command sender suggests that the other party alone                    should handle formfeeds, but suggests that                            formfeeds be simulated.                                  254          Command sender suggests that the other party alone                    should handle output formfeeds but suggests                           waiting for a character to be transmitted (on the                     other simplex connection) before sending more                         data. Note that, due to the assynchrony of the two                    simplex connections, phase problems can occur with                    this option.                                             255          Command sender suggests that the other party alone                    should handle output formfeeds and suggests                           nothing about how it should be done.    The guiding rules are that:       1) if neither data receiver nor data sender wants to handle output       formfeeds, the data receiver must do it, and      2) if both data receiver and data sender want to handle output      formfeeds, the data sender gets to do it.    The reasoning for the former rule is that if neither wants to do   it, then the default in the NAOFFD option dominates.  If both want   to do it, the sender, who is presumed to have special knowledge   about the data, should be allowed to do it, taking into account any   suggestions the receiver may make.  Simulation is defined as the   replacement of the formfeed character by enough line-feeds (only)   to advance the paper (or line-pointer) to the top of the next page   (or to the top of the terminal screen).  Note that delays,   controlled by the data sender, must consist of NUL characters   inserted immediately after the formfeed character.  This is   necessary due to the assynchrony of network transmission.  As with   all option negotiations, neither party should suggest a state   already in effect except to refuse to negotiate; changes should be   acknowledged; and once refused, an option should not be resuggested   until "something changes" (e.g., another process starts).  At any
                            time, either party can disable further negotiation by giving the   appropriate WON'T NAOFFD or DON'T NAOFFD command.