The vast majority of MUDs don't even implement the full TELNET protocol, just a small subset. In typical MUD fashion, fundamental TELNET parts like option negot

The vast majority of MUDs don't even implement the full TELNET protocol, just a small subset. In typical MUD fashion, fundamental TELNET parts like option negotiation were either hacked together -badly- or altogether ignored. For the longest time in the 90s TELNET AYT would crash tons of custom implementations.