A teacher has been reprimanded for communicating a racist and sexual phrase while teaching a pupil at a Sussex school.
James Hersey, 68, was found guilty of unacceptable professional conduct by the General Teaching Council.
The hearing heard he was teaching electronics to a Year 11 pupil at Oriel High School in Crawley when the incident happened in March last year.
Mr Hersey said he was a caring teacher who had made a mistake.
The disciplinary hearing was told Mr Hersey was teaching a student a phrase to help remember the sequence for the colour coding of resistors.
He said: "I said to him I was taught a naughty, saucy rhyme in the sixties and I've never forgotten it, and that's how I learned to remember resistor colour codes."
Mr Hersey said he only wrote down part of the phrase, a mnemonic, when pushed by the student, but the student guessed the missing words.
The incident came to light when the boy told another teacher.
Mr Hersey said: "I went into teaching after 30 years in engineering because I wanted to do some good for society.
"I am a good professional, I'm caring, and I like to teach children how to do things.
"I do regret it but I immediately apologised to the school and said I'd made a human error."
The GTC accepted he only communicated the words when pressed and was outside the formal classroom environment at the time.
But in its ruling, the panel said: "Notwithstanding that the mnemonic was not communicated in its entirety, to do so was entirely inappropriate and below the standard of conduct expected of a registered teacher."
Mr Hersey will have a reprimand against his record for two years. He has 28 days to appeal the decision.