Locked Pair
The two cells of a naked pair sit where a line crosses a box, so the digits go from both the line and the box.
How it works on this board
5 and 7 must be used within the highlighted cells
3
1
2
9
6
4
1
2
8
1
8
1
2
9
9
8
3
2
7
8
4
1
6
9
2
1
9
5
2
6
2
4
1
9
No marks yetPosition 0 / 2