Hi, it hooks into a recess that is specially shaped for it in the top left hand side of the rack plate and dangles down to the left.
I think it is meant for when the Honda 'D' lock is stored in the holes for it in the rack.
The rubber strap loops around the end of the lock and hooks over one of the domed nuts underneath.
It just stops the lock from rattling around (at least, I assume that's what it's meant for).
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