GMC Sierra 2008 Owner's Manual page 55

CAUTION:
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Each lower anchor and top tether anchor in the
vehicle is designed to hold only one child
restraint, except the center top tether anchor in
crew and extended cab models. Attaching more
than one child restraint to a single anchor could
cause the anchor or attachment 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 anchor.
CAUTION:
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Children can be seriously injured or strangled if
a shoulder belt is wrapped around their neck
and the safety belt continues to tighten. Secure
any unused safety belts behind the child
restraint so children cannot reach them. Pull the
shoulder belt all the way out of the retractor to
set the lock, if your vehicle has one, after the
child restraint has been installed. Be sure to
follow the instructions of the child restraint
manufacturer.
Notice: Contact between the child restraint LATCH
attachment parts and the vehicle's safety belt
assembly may cause damage to these parts. Make
sure when securing unused safety belts behind
the child restraint that there is no contact between
the child restraint LATCH attachment parts and
the vehicle's safety belt assembly.
Folding an empty rear seat with the safety belts
secured may cause damage to the safety belt or the
seat. When removing the child restraint, always
remember to return the safety belts to their normal,
stowed position before folding the rear seat.
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