[TELNET-PROTOCOL-DEFINITIONS]
255=IAC - interpret as command: 
254=DONT - you are not to use option
253=DO - please, you use option
252=WONT - I won't use option
251=WILL - I will use option
250=SB - interpret as subnegotiation
249=GA - you may reverse the line
248=EL - erase the current line
247=EC - erase the current character
246=AYT - are you there
245=AO - abort output--but let prog finish
244=IP - interrupt process--permanently
243=BREAK - break
242=DM - data mark--for connect. cleaning
241=NOP - nop
240=SE - end sub negotiation
239=EOR - end of record (transparent mode)
238=ABORT - Abort process
237=SUSP - Suspend process
236=xEOF - End of file: EOF is already used...

[TELNET-OPTIONS]
0=TELOPT_BINARY - 8-bit data path
1=TELOPT_ECHO - echo
2=TELOPT_RCP - prepare to reconnect
3=TELOPT_SGA - suppress go ahead
4=TELOPT_NAMS - approximate message size
5=TELOPT_STATUS - give status
6=TELOPT_TM - timing mark
7=TELOPT_RCTE - remote controlled transmission and echo
8=TELOPT_NAOL - negotiate about output line width
9=TELOPT_NAOP - negotiate about output page size
10=TELOPT_NAOCRD - negotiate about CR disposition
11=TELOPT_NAOHTS - negotiate about horizontal tabstops
12=TELOPT_NAOHTD - negotiate about horizontal tab disposition
13=TELOPT_NAOFFD - negotiate about formfeed disposition
14=TELOPT_NAOVTS - negotiate about vertical tab stops
15=TELOPT_NAOVTD - negotiate about vertical tab disposition
16=TELOPT_NAOLFD - negotiate about output LF disposition
17=TELOPT_XASCII - extended ascii character set
18=TELOPT_LOGOUT - force logout
19=TELOPT_BM - byte macro
20=TELOPT_DET - data entry terminal
21=TELOPT_SUPDUP - supdup protocol
22=TELOPT_SUPDUPOUTPUT - supdup output
23=TELOPT_SNDLOC - send location
24=TELOPT_TTYPE - terminal type
25=TELOPT_EOR - end of record
26=TELOPT_TUID - TACACS user identification
27=TELOPT_OUTMRK - output marking
28=TELOPT_TTYLOC - terminal location number
29=TELOPT_3270REGIME - 3270 regime
30=TELOPT_X3PAD - X.3 PAD
31=TELOPT_NAWS - window size
32=TELOPT_TSPEED - terminal speed
33=TELOPT_LFLOW - remote flow control
34=TELOPT_LINEMODE - Linemode option
35=TELOPT_XDISPLOC - X Display location
36=TELOPT_OLD_ENVIRON - Old - Environmental variables
37=TELOPT_AUTHENTICATION - Authenticate
38=TELOPT_ENCRYPT - Encryption option
39=TELOPT_NEW_ENVIRON - New - Environmental variables
255=TELOPT_EXOPL - extended options list