Before we can use GMCP we need to let the server know that our client supports this. In order to achieve this, first we need to create some variables that will store the bytes used for negotiation with the server trough the telnet protocol

#VAR {telnet[iac]} {\xFF};
#VAR {telnet[do]} {\xFD};
#VAR {telnet[sb]} {\xFA};
#VAR {telnet[se]} {\xF0};
#VAR {telnet[gmcp] {\xC9};

On their own, these are useless, so we create an alias that will aid us in sending GMCP commands to the server

#ALIAS {gmcp}
{
    #SEND {$telnet[iac]$telnet[sb]$telnet[gmcp]%0$telnet[iac]$telnet[se]};
}