Toyota Corolla Quick Reference Manual page 21

If belt is fully extended, then retracted even slightly, it cannot be
re-extended beyond that point, unless fully retracted again. This feature
is used to help hold child restraint systems securely.
To find more information about seatbelts, and how to install a child
restraint system, refer to the Owner's Manual.
Push up, or
squeeze lock
release to lower
Keep as low on
hips as possible
Rear seat outside
position guides
provide added
comfort for children
who have outgrown
child restraints.
19
Take up slack
Too high