Hong Kong's teaching profession has something to celebrate. Over four years, not one teacher has been found guilty of any misdemeanour that would warrant censure by the council that oversees its professional conduct. The zero indictments suggest that teachers are upholding the lofty goals of education and behaving in unblemished fashion towards both students and colleagues. There is no reason not to believe that the majority of teachers are indeed such a credit to the profession. But it may be too good to be true that this is the case of all 60,000 in Hong Kong. Scratch beneath the surface and there is talk that various kinds of unprofessional behaviour - as defined in the Code for the Education Profession of Hong Kong - are in fact quite common. Favouritism in the staffroom, as well as among teachers for their pet students, are two examples. The undermining and bullying of other teachers is another, with new and young teachers reported to be common victims in the staffroom jungle. While no cases have been proven, the number reported to the Council on Professional Conduct in Education has doubled in the past two years, to 58. At a press conference this week, its chairman, Pun Tin-chi, cited abuse of power and inappropriate behaviour as examples of the type of bad conduct it deals with. Sexual relations between teachers and their students were examples of the latter. Astonishingly, Mr Pun said the council was split on how to handle this - there being no clear guidelines to follow. This 'grey area' leaves Hong Kong students highly vulnerable and contrasts with black and white law in some jurisdictions. In the UK, for example, it is a criminal offence for a person in a position of trust - like a teacher - to engage in any sexual activity with a person aged under 18 where such trust exists, even if the relationship is consensual. The council, which relies on elected volunteers, has no powers to call witnesses. If a case is proven, all it can do is offer advice to the Permanent Secretary for Education. Teachers talk of a 'conspiracy of silence'. They might be willing to grass on a colleague in the staffroom but rarely are they willing to stand up and give official evidence. Let's hope there are very few cases that should concern us. But the limitations of this watchdog suggest the government should no longer delay delivering on its promise of creating a more robust general teaching council. As in the medical profession, cases should be handled openly. Those found to be a discredit should be suspended or struck off from practicing, not quietly allowed to move on to other schools. With children's futures in teachers' hands, too much is at stake to do less.