“The Whiz is a small, ingenious device created to revolutionise every woman’s life. Hygenic, comfortable and easy-to-use, the Whiz means that women can now pass urine in all those situations where previously it has been difficult or embarrassing to do so.” The accompanying photograph suggests something like a high-tech funnel.

So now you’ve got it. Nothing to do with marking, assessment, or planning, but everything to do with the iron bladder control required by teachers to survive the school day - a problem being discussed at some length on the TES online staffroom.

According to the teacher recommending the Whiz, it means: “You can pop into the cupboard, do what you have to and no trekking to the damned loos.”

Other correspondents, however, are made of sterner stuff, apparently being possessed of bladders a camel might envy and boasting of an ability to go without going for 12 hours or more, despite dire warnings of kidney problems to come from their colleagues.

“You have to retrain yourself after the summer holidays too. Takes a week or so but then you can keep it in for hours. Very useful skill to have when going to festivals or on long coach journeys!” says one.

Lilyofthefield adds: “Good job I did all my pelvic floor exercises after I had the kids. I bet I could hold back the banks of the Ganges.”

But the last, doleful, word should go to Crucible. “I sent a note with a child to the office asking if someone could cover my class while I popped to the loo. The headteacher sent back a rubber band.”