Visitors to The TES online staffroom have posted phrases that mean schools should be avoided. Apparently, alarm bells should ring if an advert includes the words “improving school”, “exciting times”, “challenging”, “developing” or “vibrant”.

One contributor wrote: “If it says ‘join this developing department’ it means that the head of department has taken ill-health retirement, several other people have left, and there is hardly anyone there any more.” Another wrote: “I steer well clear of ‘high standards’ and schools that will not let you sit in the staffroom when you go to visit.”

Other warning signs include adverts in which the logo takes up more space than the words, especially if the logo includes an Investor in People award.

Teachers also urged others to beware of schools with short lunch-breaks - a sign of potential behaviour problems - and schools that had recently changed their names.

But John Howson, an expert in teacher recruitment and visiting professor at Oxford Brookes University, defended schools which stressed that posts would be challenging. “Job adverts need to be designed to appeal to different types of teachers,” he said. “If you are advertising for a post in a popular subject like English or history you may only want to attract the most dedicated teachers, but if you are advertising for a head of design and technology you will probably want to attract everyone you can.”

Professor Howson said adverts were changing and that fewer now stressed computer facilities as teachers were no longer impressed.

The most worrying TES advert this month, he said, was for a secondary deputy head which said: “This is a school which prides itself on being extremely self-critical.”

Letters, 24Friday magazine, 8 www.tes.co.ukstaffroom