Extend

(1)	(2)	(3)	(4)	(5)
‘extend’ is dancers moving forward, from one tagging formation to the next

START:	END:	EXAMPLES:
		(1) moves into (2); outside couples move only slightly to adjust row spacing; centers form a right-hand wave
		(2) moves into (3); if you start with a right-hand wave in center, then move to right-hand waves (ditto for left)

START:	END:
		(3) moves into (4); if you start with left-hand waves, then move to a left-hand wave in center (ditto for right)
		(4) moves into (5); outside couples move only slightly to adjust row spacing

The fundamental idea of ‘stepping into the next line’ can apply to fewer dancers, as illustrated here: