;by interex
;for mIRC 6.12+

alias rot { 
 var %a = 1
 var %b = $lower($1-)
 while (%a <= $len(%b)) { 
  if ($mid(%b,%a,1) < n) { 
   var %c = %c $encode($chr($calc($asc($mid(%b,%a,1)) -96+13+96)),m) 
  }  
 if ($mid(%b,%a,1) > m) { 
  var %c = %c $encode($chr($calc($asc($mid(%b,%a,1)) -96-13+96)),m) 
 }
 inc %a 
 }
 return $+($remove($encode(rt,m),=),$replace($remove(%c,$chr(32),=),$chr(45),$chr(32)))
}
alias rot-d {
 var %a = 1
 var %b = $1-
 while (%a <= $len(%b)) {
  var %c = %c $decode($addtok($mid(%b,%a,2),=,2),m)
  inc %a
  inc %a 
 }
 return $rotx(%c)
 set -u %c
}
alias rotx {
 var %a = 1
 var %b = $1-
  while (%a <= $len(%b)) {
  if ($mid(%b,%a,1) < n) {
   var %c = %c $chr($calc($asc($mid(%b,%a,1)) -96+13+96))
  }
 if ($mid(%b,%a,1) > m) { 
  var %c = %c $chr($calc($asc($mid(%b,%a,1)) -96-13+96))
 }
 inc %a
 }
 return $replace($remove(%c,$chr(45),$chr(32)),$chr(58),$chr(32))
}
on ^*:text:*:*:{ 
 if ($left($1,3) = cnQ) {
  var %rot.chk = $rot-d($remove($1,$left($1,3)))
   echo -a $+($chr(3),12,::Decoding RT::,$chr(3),4,$chr(40),$nick,$chr(41),$chr(3)) %rot.chk
   haltdef
  }
}