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- TELNET OUTPUT HORIZONTAL TABSTOPS OPTION
- RFC 653, NIC 31156 (Oct. 25, 1974)
- D. Crocker (UCLA-NMC)
- Online file: [ISI]<DCROCKER>NAOHTS.TXT
-
- TELNET OUTPUT HORIZONTAL TABSTOPS OPTION
-
- 1. Command name and code
- NAOHTS 11 (Negotiate About Output Horizontal Tabstops)
-
- 2. Command meanings
- In the following, we are discussing a simplex connection, as described in
- the NAOL and NAOP Telnet options.
- IAC DO NAOHTS
- The data sender requests or agrees to negotiate about output
- horizontal tabstops 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
- horizontal tabstops.
- IAC DON'T NAOHTS
- The data sender refuses to negotiate about output horizontal tabstops
- with the data receiver, or demands a return to the unnegotiated
- default mode.
- IAC WILL NAOHTS
- The data receiver requests or agrees to negotiate about output
- horizontal tabstops 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 horizontal tabstops.
- IAC WON'T NAOHTS
- The data receiver refuses to negotiate about output horizontal
- tabstops, or demands a return to the unnegotiated default mode.
- IAC SB NAOHTS DS <8-bit value> ... <8-bit value> IAC SE
- The data sender specifies, with the 8-bit value(s), which party should
- handle output horizontal tabstop considerations and what the stops
- should be. The code for DS is 1.
- IAC SB NAOHTS DR <8-bit value> ... <8-bit value> IAC SE
- The data receiver specifies, with the 8-bit value(s), which party
- should handle output horizontal tabstop considerations and what the
- stops should be. The code for DR is 0.
-
- 3. Default
- DON'T NAOHTS/WON'T NAOHTS.
- In the default absence of negotiations concerning which party, data
- sender or data receiver, is handling output horizontal tabstops, neither
- party is required to handle them and neither party is prohibited from
- handling them; but it is appropriate if at least the data receiver
- handles horizontal tabstops, albeit primitively.
-
- 4. Motivation for the Option
- Please refer to section 4 of the NAOL and of the NAOP Telnet option
- descriptions.
-
- 5. Description of the Option
- The data sender and the data receiver use the 8-bit value(s) along with the
- DS and DR SB subcommands as follows (multiple 8-bit values are allowed only
- if each is greater than zero and less than 251):
-
- 8-bit value : Meaning :
-
- 0 Command sender suggests that he alone will handle
- tabstops, for the connection.
- 1 to 250 Command sender suggests that the other party alone
- should handle tabstop considerations, but suggests
- that the indicated value(s) be used. The value(s)
- are the column numbers, relative to the physical
- left side of the printer page or terminal screen,
- that are to be set.
- 251 to 254 Not allowed, in order to be compatible with
- related Telnet options.
- 255 Command sender suggests that the other party alone
- should handle output tabstops 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
- horizontal tabstops, the data receiver must do it, and
- (2) if both data receiver and data sender want to handle output
- horizontal tabstops, 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 NAOHTS 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.
- 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 NAOHTS or DON'T NAOHTS command.
-