Wanted: nit nurse. It is not an advert that appears with any regularity in the jobs pages of The TES. So researchers looking for the origin of the term are having trouble tracking it down.
Now teachers are being asked to help trace this and 49 other common words and phrases as part of a documentary to be screened on BBC2 next year.
The Wordhunt Project is asking viewers to help update the Oxford English Dictionary by finding their earliest occurrences. These words and phrases include several that staff may have come across long before they fell into common parlance outside the school gates.
Helena Braun, Wordhunt assistant producer, said: "We know that people were looking for nits right back into the early 1900s. But it is not written down very often. It is the language of the playground.
"The OED has learned people going through academic tomes. But for street words, or slang, school is a better place to start."
Records of a school fete, for example, may refer to a bouncy castle before its first officially recorded occurrence, in 1986. Researchers also hope that teachers will have dated essays or videos demonstrating early use of classroom slang. So far, they have been unable to find any "mingers" (unattractive people) before 1995, or records of anyone "on the pull" (looking for a sexual encounter) before 1988.
"Teachers always complain that pupils write essays in slang or text-speak," said Ms Braun. "But that does have educational value. It could be really helpful for us... as long as they've remembered to put the date at the top."
Trevor Millum of the National Association for the Teaching of English agrees that teachers are often among the first to hear new teenage slang.
But he questions whether many will have written proof of early usage. "Much as we love marking, we don't tend to hang on to past essays. Our rooms are too full of current marking."
You must remember this... when did you first hear these words?
Fifty wordsphrases with earliest recorded usage:
Back to square one (1960)
Bomber jacket (1973)
To bonk (1975)
Bouncy castle (1986)
Chattering classes (1985)
Full monty (1985)
Gas mark (1963)
Gay (homosexual) (1935)
Handbags (at dawn) (1987) Her indoors (1979)
Jaffa (cricketing term) (1993)
Moony, moonie (1990)
To muller (1993)
Mullet (hairstyle) (1994)
Mushy peas (1975)
Nip and tuck (1980)
Nit nurse (1985)
Nutmeg (football use) (1979)
Old Bill (police) (1958)
On the pull (1988)
Pass the parcel (1967)
Pick and mix (1959)
Ploughman's lunch (1970)
Pop one's clogs (1977)
Smart casual (1945)
Something for the weekend (1990)
Throw one's toys out of the pram (or cot) (1989)
Tikka masala (1975)