Last one of the WPC preparation puzzles. This is a pretty cool type, but it’s not that easy to pull off – lots of potential to run into contradictions or non-uniqueness. It’s a bit of a confusing rule, but I feel that it works out very well.
Rules Fill the empty cells with letters ABC so that each row and column contains each letter exactly once. (Ignore the clue cells.) The clue cells then indicate all letters that can be seen from that cell in both horizontal and vertical directions. The dashed clue means that there is no common letter to be seen.
Or see the instruction booklet.