How to solve this 6×6 logic puzzle

This 6×6 board rates as gentle (difficulty score 647). Solving it from scratch takes 16 logical steps, using 5 techniques: Single cell, Row/column exclusion, Adjacency clear, Region confinement, Paired regions. Every step below is forced: nothing here is a guess.

1. First, place a marker at F2. Region 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.
2. Next, every open cell left in this region sits in column C, so its marker has to land there; that clears every other open cell in the column.
3. Then, every open cell left in this region sits in column D, so its marker has to land there; that clears every other open cell in the column.
4. After that, together, two regions have open cells only in rows 1 and 3; with one marker each, those two markers have to fill exactly those two rows, so every other region's open cells there can be cleared.
5. Now, place a marker at C4. Region has exactly one open cell left. Placing here clears the rest of row 4, column C, and its region. Placing here also clears its 3 touching neighbours.
6. From there, place a marker at D1. Region has exactly one open cell left. Placing here clears the rest of row 1, column D, and its region.
7. Following that, place a marker at A3. Region has exactly one open cell left. Placing here clears the rest of row 3, column A, and its region.
8. First, place a marker at B6. Region has exactly one open cell left. Placing here clears the rest of row 6, column B, and its region.
9. Finally, place a marker at E5. Region has exactly one open cell left.

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