What are the weight and height limits for rear-facing mode?

The rear-facing mode supports children weighing 1.9–18 kg (4–40 lbs) and measuring 44–101 cm (17–40 in). The top of the child's head must be at least 2.5 cm (1 in) below the top of the car seat headrest or shell, and harness straps must be at or just below the child's shoulders. Once your child exceeds any of these requirements, they must transition to forward-facing mode if possible. (Page 10)