SudoCue Users

Hey David, I finally got it, many thanks! I think I am getting hooked with Soducue now.

Dear Sudocue fans, Under "Sudoku Solving Guide", there is an example for "Locked Candidates (type 2)". Could someone please explain why box 5 can't have 7 in Column 4 or Column 6 (highlighted in red). With all the given digits shown, I somehow failed to understand this topic. Tha...