Normal sudoku rules apply. Adjacent digits along a green German whisper line must differ by at least 5. Both digits (which can be equal) on the endpoints of a green line form a look-and-say clue. If for example the digits on both endpoints of a line are 4 and 3, then the digit 3 has to appear exactly four times on this line AND the digit 4 has to appear exactly three times on the line. The line that starts in R2C6 ends at R2C8.