$randtok - it's returning a random sequence of tokens.

Syntax: $randtok(A,B,C)
A - amount of signs
B - 1 (big letters), 2 (small letters)
C - the ascii value of the character separating the tokens. If not given, signs are by themselves.

Example:
//echo -a $randtok(5,1,32)

//echo -a $randtok(4,2)

alias randtok {
  unset %randtok
  var %a = 1, %b = $1
  while (%a <= %b) {
    var %c $rand(1,2)
    if (%c == 1) var %randtok. [ $+ [ %a ] ] $rand(0,9)
    else var %randtok. [ $+ [ %a ] ] $iif($2 == 1,$rand(A,Z),$rand(a,z))
    inc %a
  }
  var %c = 1, %d = $var(%randtok.*,0)
  while (%c <= %d) {
    set %randtok $+(%randtok,$chr($3),$var(%randtok.*,%c).value)
    inc %c
  }
  return $iif($chr($3) == $left(%randtok,1),$right(%randtok,$calc($len(%randtok) - 1)),%randtok)
}