Can an edge cell belong to a later clue?

Sometimes. Check the clue order and known empty cells before extending a group.

X marks are confirmed empty cells. They protect the solved groups and make the remaining clue placements clearer.

Nonogram guide

How Edge Clues Work in Nonograms

Learn how filled cells touching the border can force nonogram groups to expand inward.

Quick answer

If a clue group starts at the edge, it often has only one direction to grow. That can force additional fills and separator X marks.

Search intent: Technique query for players who know the rules but miss edge deductions.

A filled cell in the corner or along the border removes one side of uncertainty. If it belongs to a large clue, the run may have to extend inward.

When a clue group is complete, mark the cell after it as empty if it is inside the grid. This prevents accidental merging with another group.

Edge logic becomes stronger when a row clue and a column clue both constrain the same cell.

Practice edge clues with guided picture-logic puzzles.