English: Edges and corners of a square sail are shown on the uppermost sail:

• The sail is attached to a spar (or yard ) at its head and tensioned outwards at the head cringles .
• The side edges are the leeches .
• The bottom edge is the foot and is attached to the yard below by sheets (not labelled) at the clews which are the corners.

Running rigging is shown on the lower sail:

• The lifts are shown slack, because the spar (or yard) is raised, but would support the lowered spar, as shown on the topmost spar.
• The sheets pull the clews down to the yard below when setting sail.
• The clewlines raise the clews to the yard above when dousing (striking or furling) sail.
• The halyard raises a yard into place, seen as two line converging on a block, which is attached to a line that goes up to the crosstrees and through a sheave to raise the yard.
• The braces adjust the sail side-to-side by tension applied from below to a block on the spar, countered by tension at the other end on a mast behind the spar, pulling one end aft and allowing the other end to rotate forward.