As per Relevance of the word specifies, we have this rfc below:
Network Working Group B.
Request for Comments: 1097 CMU-
1 April 1989
TELNET SUBLIMINAL-MESSAGE
Status of this
This RFC specifies a standard for the Internet community. Hosts
the Internet that display subliminal messages within the
protocol are expected to adopt and implement this standard
Distribution of this memo is unlimited
1. Command name and code
SUBLIMINAL-MESSAGE 257
2. Command meanings
IAC WILL SUBLIMINAL-
The sender of this command REQUESTS permission to, or
that it will, display subliminal messages
IAC WONT SUBLIMINAL-
The sender of this command REFUSES to display subliminal messages
IAC DO SUBLIMINAL-
The sender of this command REQUESTS that the receiver, or
the receiver permission to, display subliminal messages
IAC DONT SUBLIMINAL-
The sender of this command DEMANDS that the receiver not
subliminal messages
IAC SB SUBLIMINAL-MESSAGE <16-bit value> <16-bit value>
The sender specifies a message to be subliminaly displayed by
remote host. If the client has agreed (via the standard WILL
DO DONT mechanism) to display subliminal messages, it must
this subnegotiation and attempt to display the message string
the users console for the specified duration and continue to do
at fixed intervals until another SUBLIMINAL-MESSAGE
is received. The position and rendering of the message
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RFC 1097 SUBLIMINAL 1 April 1989
implementation dependent
The first 16-bit value specifies the duration of the message
milliseconds. It is sent MSB first. The second 16-bit
specifies the frequency with which the message is displayed.
represents the number of seconds between displays and is also
MSB first. The final parameter is the message itself
The syntax for this subnegotiation is
IAC SB SUBLIMINAL-
DURATION[1] DURATION[0]
FREQUENCY[1] FREQUENCY[0]
MESSAGE_
IAC
As required by the Telnet protocol, any occurence of 255 in
subnegotiation must be doubled to destinguish it from the
character (which has a value of 255).
3. Default
WONT SUBLIMINAL-
DONT SUBLIMINAL-
i.e., subliminal messages will not be displayed
4. Motivation for the
Frequently the use of "Message of the day" banners and newsletters
insufficient to convince stubborn users to upgrade to the
version of telnet. Some users will use the same outdated version
years. I ran across this problem trying to convince people to
the REMOTE-FLOW-CONTROL Telnet option. These users need to be
"persuaded".
5. Description and implementation notes
The quality of the client implementation will depend on it's
to display and erase text strings in a small amount of time.
current implementation at CMU takes into acount terminal line speed
advanced video capabilities, and screen phospher persistance
calculating how long to wait before erasing a message
While it is permitted for the client to display the message
"in-line", best results at obtained by printing the message at
top or side of console screen where it will just catch the corner
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RFC 1097 SUBLIMINAL 1 April 1989
the user's visual field
A version is currently under development at CMU to display
message using morse-code over the keyboard caps-lock LED
6.
In the following example all numbers are in decimal notation
1. Server suggests and client agrees to use SUBLIMINAL-MESSAGE
(Server sends) IAC DO SUBLIMINAL-
(Client sends) IAC WILL SUBLIMINAL-
(Server sends) IAC SB SUBLIMINAL-MESSAGE 0 5 0 20 "Use VMS" IAC
[The server is "suggesting" that the user employ a
operating system, not an unreasonable request...]
The client should immediately begin displaying the message
should continue to do so at regular intervals
2. Server preempts previous subliminal message
(Server sends) IAC SB SUBLIMINAL-MESSAGE 0 5 0 20 "Go home" IAC
The client should now no longer display the previous message
should immediately begin displaying the new one
3. Server has messed with user enough for one day
(Server sends) IAC SB SUBLIMINAL-MESSAGE 0 0 0 0 "" IAC
The client must cease display of any subliminal messages
7. Acknowledgements
We do things just a little sneakier here at CMU
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if you see any problems within the linking, don't worry be happy,
this is version 0.1 of the Relevance System and you gotta expect some crappy subroutines sometimes,
just be content we did not write this in Java, which would have made this "bigger and better" HAHAHHA.
RFC documents can be found at I.E.T.F.
Relevance System Copyright © 2002 Spectrum WorldResearch
other technical nosh by ServerMasters Corporation
collaboration of BobX
