There are missing entries in the above chart. This means that piece containing charactes with missing entries cannot be flipped in certain direction. Pieces containg characters not in above chart cannot be flipped at all. For example, flipping upside-down an underscore "_" or dot is forbidden. Flipping horizontally a comma "," is forbidden too, but you can flip it upside down, and then the resulting "`" can be flipped in both directions. After any flipping has been applied, Krogg's rules apply: > two pieces that fit togather like so: > ,-------.----. > | __/ | > | (_ | > | _/ | > | ( | > `----`-------' > are drawn like so: > ,-------. .----. > | __/ __/ | > | (_ (_ | > | _/ _/ | > | ( ( | > `----` `-------'
Source: https://ascii.co.uk/art/puzzle