But it is not just pupils who are at the receiving end of these killer lines. According to contributors to The TES online staffroom, classroom teachers are similarly vulnerable as heads seek to prove that the verbal sword is mightier than the red pen.
One teacher tells of an annual appraisal, in which she was casually informed that she might be eligible for further promotion: "If you ... get a suit, shoes with small heels, a smart hairstyle, small earrings and a little bit of make-up."
Another was curtly informed at the end of a job interview that she had simply been outclassed by the rest of the applicants: a euphemistic "could do better".
But wounding remarks are not the preserve of heads. One teacher reports how, as a member of staff, she was told by her mentor: "When I was an NQT, I used to be up until midnight every night working. If you're not prepared to do that, you're not committed."
Indeed, any sign of wavering commitment to one's duty often results in a sharp rebuke from a senior manager.
When one teacher told her deputy head that she had been diagnosed with a heart condition and would have to take four weeks off school, the deputy replied: "Four weeks? What are we going to do about Mary's coursework?"
Even the most dedicated teachers can be put in their place for daring to complain. Reporting that she had been hit by a pupil in the classroom, one teacher was told to get back to work. Physical abuse, the head declared, was an occupational hazard.