How to solve this 6×6 logic puzzle

This 6×6 board rates as gentle (difficulty score 551). 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 row 5, so its marker has to land there; that clears every other open cell in the row.
2. Next, every open cell left in this region sits in row 6, so its marker has to land there; that clears every other open cell in the row.
3. Then, every open cell left in this region sits in row 4, so its marker has to land there; that clears every other open cell in the row.
4. After that, every open cell in column A belongs to the same region, so that region's marker has to be somewhere in this column; that clears every other open cell in the region.
5. Now, place a marker at B4. Column 2 has exactly one open cell left. Placing here clears the rest of row 4, column B, and its region. Placing here also clears its 2 touching neighbours.
6. From there, place a marker at C1. Column 3 has exactly one open cell left. Placing here clears the rest of row 1, column C, and its region.
7. Following that, place a marker at A2. Region has exactly one open cell left. Placing here clears the rest of row 2, column A, and its region.
8. First, place a marker at D6. Column 4 has exactly one open cell left. Placing here clears the rest of row 6, column D, and its region. Placing here also clears its 1 touching neighbour.
9. Next, place a marker at F5. Region has exactly one open cell left. Placing here clears the rest of row 5, column F, and its region.
10. Finally, place a marker at E3. Region has exactly one open cell left.

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