What does the Highway Code recommend when parking a manual car facing downhill?

Apply the handbrake, select reverse gear and turn the steering wheel towards the kerb.

NI Highway Code rule 252 gives this downhill advice as an extra precaution against a vehicle rolling. When parking uphill it advises a forward gear and wheels away from the kerb. Automatic vehicles should use Park. Always consider the actual slope and kerb and make sure the vehicle is secure before leaving.