Teachers are constantly wary of potential threats to their professionalism - low pay, classroom assistants taking lessons. And the open-toed sandal.
It has been a hot topic in the TES online staffroom forum lately. Just how acceptable is it for teachers to reveal toe-cleavage in the classroom?
One teacher said: "Sandals, shorts and short-sleeved shirts are all entirely unacceptable in my view. Teachers want to be seen as professionals, but I've never seen any other professionals - solicitors, doctors, bankers - wearing sandals."
Others are more direct in their criticism: "Open-toed sandals at work merely mean you are English and have no fashion sense," said one contributor. Another writer said: "Sandals are a must. Most other professionals work in air-conditioned buildings. Closed-in shoes make your feet stink."
But, unlike other professionals, teachers have to take health and safety issues into consideration. "Trodden-on feet!" said one contributor. "Ouch!"
Another was more explicit: "Last week, I dragged a table over my three-inch wedge-heel sandals. A pain I cannot forget. A stain I cannot remove."
And there are limits to the degree to which teachers are prepared to suffer for fashion. One teacher has sworn off open-toed sandals since a pupil threw up over her feet. "Picking vomit from between your toes is not good,"
Some contributors got personal: "Only if your toenails aren't nicotine-stained," and "If you are a dame, then OK so long as you are not too long in the tooth or toenail."
"What about toe rings and nail polish? If it's OK for the students then I think it is OK for the staff."
In some schools, the most scathing judgement is reserved for male teachers who expose unnecessary foot flesh. Several teachers comment on the acceptability of sandals and shorts for women, while men are censured simply for removing their ties.
One contributor said: "I think men in gawky leather sandals look geeky and so unattractive."
But on one aspect there is no dissension: "Smart-ish, sensible sandals are one thing. Sandals and socks? Now that's a whole other issue."