At the end of a recent visit from Her Majesty's Inspectors, a school was asked to provide a bill for their lunches. The business manager promptly complied and received immediate payment.
However, he was more than a little horrified when he realised that, printed on the receipt he was about to hand over to the inspector - in line with best customer service - was the seductive: "Thank you! Please call again!"
At least it didn't bear the time-honoured phrase: "Do not ask for credit, as a refusal often offends."