GMC 2003 C4C042 Owner's Manual page 58

In Canada, the law requires that forward
restraints have a top strap, and that the strap be
anchored. In the United States, some child restraints also
have a top strap. If your child restraint has a top strap, it
should be anchored.
Anchor the top strap to one of the following anchor
points. Be sure to use an anchor point located on the
same side of the vehicle as the seating position where
the child restraint will be placed.
Each top tether bracket is designed to anchor
only one child restraint. Attaching more than one
child restraint to a single bracket could cause the
anchor to come loose or even break during a
crash. A child or others could be injured if this
happens. To help prevent injury to people and
damage to your vehicle, attach only one child
restraint per bracket.
-
facing child
Once you have the top strap anchored, you'll be ready to
secure the child restraint itself. Tighten the top strap
when and as the child restraint manufacturer's
instructions say.
CAUTION:
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