An Easy 11×11 Puzzle Solved with Line Confinement in 17 Steps

This 11×11 board rates as easy (difficulty score 581). Solving it from scratch takes 17 logical steps, using 5 techniques: Single cell, Row/column exclusion, Adjacency clear, Region confinement, Line confinement. Every step below is forced: nothing here is a guess.

1. First, every open cell left in this region sits in column A, so its marker has to land there; that clears every other open cell in the column.
2. Next, place a marker at B9. Region has exactly one open cell left. Placing here clears the rest of row 9, column B, and its region. Placing here also clears its 2 touching neighbours.
3. Then, place a marker at C11. Region has exactly one open cell left. Placing here clears the rest of row 11, column C, and its region. Placing here also clears its 1 touching neighbour.
4. After that, every open cell left in this region sits in row 10, so its marker has to land there; that clears every other open cell in the row.
5. Now, every open cell left in this region sits in row 8, so its marker has to land there; that clears every other open cell in the row.
6. From there, every open cell left in this region sits in row 7, so its marker has to land there; that clears every other open cell in the row.
7. Following that, every open cell left in this region sits in column J, so its marker has to land there; that clears every other open cell in the column.
8. First, place a marker at K8. Region has exactly one open cell left. Placing here clears the rest of row 8, column K, and its region.
9. Next, every open cell in row 1 belongs to the same region, so that region's marker has to be somewhere in this row; that clears every other open cell in the region.
10. Then, place a marker at F2. Row 2 has exactly one open cell left. Placing here clears the rest of row 2, column F, and its region. Placing here also clears its 2 touching neighbours.
11. After that, place a marker at A3. Row 3 has exactly one open cell left. Placing here clears the rest of row 3, column A, and its region.
12. Now, place a marker at I4. Row 4 has exactly one open cell left. Placing here clears the rest of row 4, column I, and its region. Placing here also clears its 1 touching neighbour.
13. From there, place a marker at J6. Region has exactly one open cell left. Placing here clears the rest of row 6, column J, and its region.
14. Following that, place a marker at E5. Region has exactly one open cell left. Placing here clears the rest of row 5, column E, and its region.
15. First, place a marker at G10. Region has exactly one open cell left. Placing here clears the rest of row 10, column G, and its region.
16. Next, place a marker at H7. Region has exactly one open cell left. Placing here clears the rest of row 7, column H, and its region.
17. Finally, place a marker at D1. Region has exactly one open cell left.

The key move here was Line confinement. Once you can spot that, this board falls quickly. ∎