Horn not working

And doors , bonnet , fuel flap , boot , oil/coolant level . Vehicle ID etc . Does it say anywhere that prechecks should be done with ignition on or off to unlock or open doors etc ? We don't all have specific vehicle experience or knowledge of how some systems work . Renault Trafic brake lights are a good example . A lot only work when the engine is running and not with just the ignition turned on . Would you fail one for brake lights not working if you checked them and reverse lights with the ignition turned on and the engine not running ?