on *:join:#:{
 if ([SD]Serpent ison $chan) { part $chan You already have a SeRpEnT bot on this channel. } { halt }
 if ([SV]Serpent ison $chan { part $chan You already have a SeRpEnT bot on this channel. } { halt }
 if ([SR]Serpent ison $chan { part $chan You already have a SeRpEnT bot on this channel. } { halt }
}