How times have changed. People are surprised when a primary headteacher in North Wales writes to parents to say he will no longer tolerate swearing in school. Similarly, the correct decision of a Swansea head not to accept pupils wearing the wrong school uniform became front-page news.
School leaders are finding their decisions to exclude unruly pupils are being overturned by appeal panels and, in some cases, they are forced to accept them back into school. Staff who try to maintain good behaviour can find themselves being told by disaffected pupils that their human rights are being abused.
Whereas 30 years ago heads and staff could take parental support for granted, too many now feel isolated, even condemned, when they take moral stands.
Heads can only manage their schools in loco parentis if they have the full support of parents, community, local education authority and governing bodies. Without it, they know they are skating on thin ice.
The chief inspector's annual report for England, published last week, suggests that one in 10 secondary schools is now out of control and needs regular inspections on pupil behaviour and classroom discipline.
Fortunately, this is not the case in Wales. There are probably only a handful of schools which currently have serious disciplinary problems.
However, there are some worrying signs that things could get worse.
The number of pupil exclusions continues to rise in some schools. Bullying and antisocial behaviour is becoming endemic in a small number. Truants are getting younger, with 35 per cent starting their histories of absenteeism during primary school.
The Welsh inspectorate Estyn has not found it necessary to place schools into special measures very often. But schooling in England is being forced up a cul-de-sac, with rising standards but increasing numbers of failing schools. Wales needs to be different from England.
We need to ensure that academic standards and improvements in pupil behaviour, truancy rates, the number of exclusions, reduced bullying and better parental support occur simultaneously. Then heads will enjoy better parental, community and political support.
Professor Ken Reid is deputy principal of Swansea Institute of Higher Education and author of Truancy: short and long-term solutions, published by Routledge Falmer