Network Working Group Dave Crocker, Rand-ISD Request for Comments: 729 (Dcrocker at Rand-Unix) NlC: 40306 13 May l977 TELNET Byte Macro Option 1. Command name and code: BM 19 2. Command Meanings: IAC WILL BM The sender of this command REQUESTS or AGREES to use the BM option, and will send sing1e data characters which are to be interpreted as if longer data strings had been sent. IAC WON'T BM The sender of this option REFUSES to send single data characters which are to be interpreted as if longer data strings had been sent. IAC DO BM The sender REQUESTS or AGREES to have the other side (send of WILL BM) issue send single data characters which are to be interpreted as if longer data strings had been sent. IAC DON'T BM The sender REFUSES to allow the other side to send single data characters which are to be interpreted as if longer data strings had been sent. IAC SB BM IAC SE where: is the data byte actually to be sent across the network; it may NOT be Telnet IAC (decimal 255). RFC #729 Telnet Byte Macro Option Page 2 is a one-byte binary number, indicating how many characters follow, up to the ending IAC SE, but not including it. is a string of one or more Telnet ASCII characters and/or commands, which the is to represent; any character may occur within an . The indicated will be sent instead of the indicated . The receiver of the (the sender of the DO BM) is to behave EXACTLY as if the of bytes had instead been received from the network. This interpretation is to occur before any other Telnet interpretations, unless the occurs as part of a BM subcommand; in this case no special interpretation is to be made. Note that the effect of a particular may be negated by reseting it to "expand" into itself. is decimal 01. IAC SB BM IAC SE The receiver of the for accepts the requested definition and will perform the indicating expansion whenever a is received and is not part of a BM subcommand. is decimal 02. IAC SB BM IAC SE The receive of the for refuses to perform the indicated translation from to either because the particular is not an acceptable choice or because the length of the exceeds available storage. is decimal 03. may be which is decimal 01; or which is decimal 02. RFC #729 Telnet Byte Macro Option Page 3 IAC SB BM IAC SE The is to be treated as real data, rather than as representative of the is decimal 03. 3. Default: WON'T BM -- DON'T BM No reinterpretation of data is allowed. 4. Motivation for the option: Subcommands for Telnet options currently require a minimum of five characters to be sent over the network (i.e., IAC SB