Star Thru: use 'patticake' handhold.
Couples Hinge:
 Not a bend the line - show the difference.
 Involves square breathing from both parallel 2FL and Tidal.
Walk & Dodge - is a split circulate without changing your facing direction.
Single Hinge - what is the difference between Single Hinge and Touch 1/4?
1) Single Hinge starts from a Mini-Wave (R-H or L-H) whereas Touch 1/4 
starts from Facing Dancers (but sometimes a R-H Mini-Wave).
2) Touch 1/4 always is with the R-H, whereas Single Hinge is with the joined hand.
Trade By:
From formations where the outsides are an Out-Facing Couple
and the Centers are Facing. 
Centers Pass Thru as Outsides Partner Trade.
Should be disallowed by Inverted Lines, 3 By 1 Columns, etc.
Our definition should explicitly say that the outsides must be a Couple,
so we can't do Trade By fomr Inverted Lines, etc.
Add: Separate, go around 2, meet at Home