On National Service, I was standing on parade before Norman Shilson, a wonderfully witty sergeant major, when Signalman Johnson, he of the dirty rifle, pleaded with him for leniency.
"Oh God!" said the desperate signalman.
The sergeant-major narrowed his eyes.
"Are you going over my head, Johnson?"
He was being uncharacteristically modest in assuming himself to be outranked by God. All the same, there's a general point here, familiar to all teachers, about the business of what aggrieved parents usually refer to as "taking the matter further".
As your career progresses you'll inevitably find yourself on both sides of this. Sometimes, you'll be the one who, like Sergeant-Major Shilson, is about to be bypassed, and, at others, as a middle or senior manager, you'll be the appeal court.
Either way, it's a delicate business: you want to be fair to everyone, most of all the family. This is how, in my experience, it ought to go.
If you're the teacher complained of, go straight to your manager (get there before the complaint) and be totally honest about what happened. You cannot afford to put your manager on shaky ground when the parental interview arrives. Honesty takes the edge off all but the worst and most calculated of offences. I have a strong memory, when I was a head, of a young teacher admitting to me that he'd struck a child in temper. He wept a little at his own foolishness, and it was obvious it would never happen again. He's now been a successful headteacher for 10 years.
If you're receiving the complaint, say you'll look into it. But make sure you do, and put pressure on to get the truth. Then, when the parents return, if there's blame to be accepted, take it on behalf of the school (not the individual - most failures start with faulty management anyway) and apologise. ("We do our best but we've clearly let you down this time.") In the overwhelming majority of cases, frankness, honesty and straight, firm talk will carry the day, and with each successive example of fair dealing, your credit in the community will grow.
And, of course, you'll keep the top management in the picture all the way through. If it all ends up with a teacher being taken to task, or even disciplined, then that's a decision for the head. So make sure you've kept a good, accurate log of the whole episode.