20.05.2022, 04:52
I don't know about 1 and 3, but I can answer 2 and 2a:
2. A complete set of dominoes means, that for a number n, every set {x, y} of numbers x, y <= n appears (exactly once) as a domino pair. It should be used for puzzles like domino search (see http://wiki.logic-masters.de/index.php?t..._search/en, there you can also find a complete domino set for n=2). If you just use standard two-cell killer cages in a sudoku, you shouldn't use this tag.
2a. The best translation for the chess knight is "Springer" (one can also say "Pferd" to the chess piece, but it's less common). "Ritter" is the direct translation of "knight", but it has nothing to do with chess.
2. A complete set of dominoes means, that for a number n, every set {x, y} of numbers x, y <= n appears (exactly once) as a domino pair. It should be used for puzzles like domino search (see http://wiki.logic-masters.de/index.php?t..._search/en, there you can also find a complete domino set for n=2). If you just use standard two-cell killer cages in a sudoku, you shouldn't use this tag.
2a. The best translation for the chess knight is "Springer" (one can also say "Pferd" to the chess piece, but it's less common). "Ritter" is the direct translation of "knight", but it has nothing to do with chess.