What's easy to use, you display it in a public place and is designed for emergency use when things get hot? A complaints policy.
OK, "fire extinguisher" might have been a better answer, but the two have a lot in common. They both might never have to be used, but if they are needed, then nothing else will do.
You should ensure parents know that if they have a complaint there is a procedure for getting it addressed.
That doesn't mean doling out the policy at the school gates but informing them where they can access it. The prospectus is a good place for telling them, as is a notice on a board in the school's entrance hall.
The heart of the policy should be the procedure for handling a complaint. Usually this mean lodging it with the headteacher or another member of the senior leadership team. If the complainant is still unhappy, it is referred to the chair, and if still unresolved it then goes to a panel of governors.
It is essential that none of the panel have any pevious knowledge of the complaint. This is one reason why governors should not get involved earlier in the procedure, let alone take up the cudgels on behalf of the complainant. If you are approached by a parent, don't walk away but refer them to the procedure and listen without commenting if they want to tell you about the problem.
Fire extinguishers have to be checked and certified annually. Make sure your complaints policy is checked regularly too, and that it is still applicable to the school's circumstances.
Having to deal with complaints is part of being accountable. An angry parent is still a stakeholder, and a complaint can be a sign that something is wrong. Ignoring it could mean you soon have a blaze on your hands.
Stephen Adamson, Vice-chair, National Governors Association.