ALISON WILLCOCKS is entirely clear about sex and drugs: any pupil found to be involved in either while her school is responsible for them must expect to be expelled. Drinking and smoking are also against the rules and pupils must expect to be punished and their parents to be informed.
Such clarity is becoming increasingly rare among the headteachers of the country's major independent schools, many of whom now give students second and sometimes third chances. So to find it at Bedales School, in Petersfield, Hampshire, the notoriously liberal school choice of many a rock star or film-maker, is to find the world stood on its head.
But Willcocks, the first female head of the school, sees no conflict with Bedales' central philosophy of respecting children and allowing them to be themselves. Teenagers, she says, need a big playing field to roam on, but they also need to know where the boundaries are."They need to be listened to, they need to be with adults who value them, they need to feel safe and valued and part of a community that doesn't constrain them too much and where they have some ownership of the values of that community.
"But they also need to be really clear where the edges are and what will happen when they step over them. And perhaps even more so in a liberal school than in any other."
This precision of thinking would have gladdened the heart of the school's founder, John Haden Badley, who broke with the tradition to create a caring, child-centred alternative to the harsh world of Victorian public schools.
Last year, as Bedales celebrated 100 years of his co-educational vision with productions in its stunning new pound;2 million theatre and A-level results that sent the school leaping up the league tables, Willcocks could have sat back and basked in the knowledge that she had steered the school safely back on course after an unsettled period a few years before.
Back then, Ian Newton, appointed as head from Rugby, was struggling to adapt to the ethos of the school which, while in no way as exceptional as it once was, nevertheless accepts casual dress and manners, first names for all, has few rules and a strong bias towards the expressive arts. When he left, abruptly, four years ago last Christmas, Willcocks, then deputy head, stepped in.
"People, including The Good Schools Guide, will tell you that I was running the school already, but although I was very involved, that actually wasn't true," she says. Nevertheless she was the obvious safe pair of hands for the governors to turn to, having been in and around the school for almost two decades.
She first came as the young, pregnant wife of Jonathan Willcocks, son of the musician David Willcocks, who was taking up an appointment as the school's director of music. Very soon, in the inclusive way of the school, she was drawn in to teach history - she has degrees in both music and history - then moved on to campus as a house mistress, before becoming deputy head. On the way, she and her husband - by then working in London - got divorced and she married the admissions secretary, a move which not only made her the mother or stepmother of six Bedalians but also her husband's boss.
"Coming here was a dream fit for me, an absolute revelation," she says. "One takes it for granted now, but what I remember is the extraordinary quality of the relationships, the liveliness, the wonderful cultural life, and the sense of community.
"I inspect schools for the HMC (Headmasters' and Headmistresses' Conference), I speak at conferences and I'm in and out of a lot of schools, and I know that the atmosphere here is qualitatively different from any other school. If you could define it, you could bottle it and sell it and make a lot of money. You could even sell it to parents to make happy families."
But not everyone agrees. The school arouses strong feelings, both for and against, with some critics seeing it as "smug", while inspectors recently found that not all pupils were able to rise to the level of self-organisation and motivation that the school expected of them.
Yet no one accuses Willcocks of complacency. Her warm manner and deep commitment to the school's values are married to a thoughtful intelligence and stern resolve. As head she has not only redrawn pupils' boundaries but has started to look at the shape of the school day, at how to maximise students' potential and at ways the school can build links beyond its 120-acre campus.
"She is tough, clear-sighted, articulate and open to change," says Jonathan Taylor, the deputy head appointed from the maintained sector. "In a place where the cry 'That's not Bedalian!' can go up, she would never say: 'That's not the way we do things here'."
"Alison?" says Jo Horsley, an upper-sixth student. "I think most people like her, but some people think she can be too harsh."
But a younger student has a quite different criticism. "She's okay - but a bit too student-friendly."
Less qualified is the response she draws from the staid HMC, where she was secretary of the co-education group and has been active in training boarding-school staff. "Smashing", "delightful", "a lovely person", are the descriptions used by her headmaster colleagues.
Ian Small, headteacher of the independent Bootham School, in York, who has shared a conference platform with her, says: "She's a person of tremendous vigour, with some stimulating thoughts about education and particularly about the way boys and girls grow up together and about how we can help them develop what you might call their affectionate side. And she's perfectly capable of being provocative if she wants to be."
All of which could stand her in good stead when the time comes to think about leaving Bedales and looking to a different future - perhaps writing, consulting or training.
"I can't imagine ever wanting to run another school," she says. "I'd be far too frustrated by the structures and imperatives in operation. I'd just want to turn it into another Bedales, which wouldn't necessarily be right."