Normal sudoku rules apply. No two instances of the same constraint type may share digits. So, although digits may repeat on a clue, they may NOT repeat across different occurrences of that clue type. Eg if an arrow has the digit X, X may repeat along that arrow, but X may not appear on any other arrow. Clue types: 1) Quadruples: In an orange circle, the question mark contains the set of all the (possibly repeating) digits appearing in the surrounding cells. 2) Renban: Digits on a purple line form a set of non-repeating consecutive digits, in any order. 3) Arrows: Digits along an arrow sum to the digit in that arrow's circle. 4) White dot: Digits separated by a white dot are consecutive. 5) Black dot: Digits separated by a black dot are in a 1:2 ratio (ie one digit is double the other).