'WAITER! My carpaccio is not cooked and the vichyssoise is cold and I distinctly remember asking for my steak tartare to be well done and the butter's like rock and no one's changed our ashtray for at least five minutes and for Christ's sake stop filling our glasses with wine every 10 seconds ...' and on it goes. We've all heard them, the whingers and moaners who go out for a meal and end up turning the affair into a nightmare for their companions, the waiter, the chef, the manager, the other diners, probably the taxi driver on the way home, the amah and the dog.

Complaining is an integral part of the restaurant business. But when the customer is always right, there's not a lot restaurateurs can do apart from grin and bear it. 'Your whole objective is to make the guy happy,' says Max Schnallinger, of ChinaMax.

Most of us never quite reach the dizzy heights in life we expect and now and again we like to give ourselves a bit of a lift. For some this is a simple task. They walk into a restaurant, sit down and treat the staff like bonded serfs. I order, therefore I am more important. 'Don't you know who I am?' is a favourite piece of rhetoric.

This can sometimes be taken a step further, according to Barry Kalb, owner of Marco Polo Pizza which employs a fleet of maniacs on scooters to speed pizza to your home. 'People who live, say, 25 minutes from our nearest delivery station phone up at the busiest time, such as nine o'clock on a Sunday evening, and they want a pizza now! Our man on the phone will explain that it might take an hour because of the distance and the pressure of business at that hour. They explode. They call him names and then they say that they know Barry Kalb and that they'll have the poor guy's job first thing in the morning. They try it on.' So who are these moaners? People who expect the whole world to drop everything just for them, says Mr Kalb, who also owns Il Mercato in Lan Kwai Fong. 'They are people with chips on their shoulders. The worst are Americans, British and Germans, or let's say that there are more bad people among those nationalities. Occasionally the Italians and French make a fuss, but the Chinese are non-confrontational, if there's something they don't like they just don't come back.' Complaining with your feet is a relatively easy option in Hong Kong, but the voiced promise never to return is often an idle threat. 'You know that once they start, nothing is going to be right,' says Karin Joffe, chef at California. 'The funny thing is that they often swear they're never going to come back, but they do. I guess they just have to feel they have some kind of power.

'What I don't understand is people who don't know what they're on about. There was a guy who had Cornish gamehen, that's what it was and that's what it said on the menu. But he insisted it was pheasant. He seemed to think we were trying to palm him off with something. He ended up writing a long, nasty letter. Totally confused.' There's another type of moaner who is closely related to the pickpocket and the card sharp. He or she is either a cool calculator or was spoiled rotten as a child and found out that a tantrum here and there bears fruit. This species knows a good moan can be lucrative.

'I once served a drink to a customer,' recalls Richard Feldman, chairman of the Lan Kwai Fong Association. 'It was a vodka tonic, completely clear except for a slice of lemon. Later, he called me over complaining that there was a cockroach in the glass. If I hadn't mixed the drink and served it myself I would never said what I said next: 'You put it there.' He was silent for a moment. Then he said: 'Oh, my God', realising he'd been caught. He admitted it and showed me a collection of bugs he carried around in a plastic bag. But he was quite unashamed.' The paradox is: why don't people complain more often when there is a real problem, and why people who do complain usually do so for the wrong reasons? How can a restaurant manager sort out the genuine gripes from the ego trips? 'What people have to realise is that restaurants are constantly trying to please as broad a range of personal tastes as possible. So you get complaints from some people that a dish is too spicy and from others that the same dish is not spicy enough,' says Tony Souza, who runs Al's Diner and Beirut. 'Or one person says the air-conditioning is too cold; another says it isn't high enough. They get the staff running all over the place twiddling dials.' On the other hand, people's deviousness is unbounded. Mr Feldman tells of the time he was working at a restaurant in Montreal with more than 1,000 seats. There was a table of four women, one of whom had mustard spilled on her dress which had been apologetically wiped off. A little later she overheard another table complain about something and get a complimentary meal for their trouble.

'So what did she do? She placed mustard on her own dress once again and then complained. Of course we had to comp her and her friends. Next day, she writes a letter demanding C$1,000 [HK$5,500] for the dress to be replaced. We offered her dry cleaning but she never sent in the dress.' There is an old joke: 'Waiter, what's this fly doing in my soup?' 'Looks like the breast stroke, sir.' Mr Feldman also recalls a restaurant which was absolutely spotless. One night a customer ordered a dish which turned out to have tiny flying bugs in it, like little fruit flies. 'We offered her a stiff drink - she'd eaten some of it. And she ordered something else. Meanwhile I went off this station.

'Some while later a waiter came to me and said another case of bugs had been found. I went over and, you wouldn't believe it, it was the same woman ...' Up at The Peak Cafe, Martin Allies remembers a sunny afternoon when a man eating outside at the terrace refused to pay his bill because, he claimed, a passing bird had dropped a speck of sewage into his food. 'But he ate it all up.' One man who admits to being an inveterate complainer is graphic designer Phil Rosenburg, a strict lacto-vegetarian for the last 30 years. He believes he has had good reason to moan. 'I go to a lot of functions in hotels and one of my gripes is the lack of imagination and choice. These might be four or five star places and their response to me is, 'Oh my god, he's a veggie. Give him a cutlet or a curry, he doesn't care.' I once said to a food and beverage manager, 'I hope you like curry, 'cos I'm gonna dump it all over your desk.' However, the situation is much better than it was.' In the end, the restaurateur is at our mercy. Bentley's fish restaurant has a log book in which all complaints, however small, are noted. 'Cancelled: one steak and kidney pudding; taste not good', one entry reads.

'Even if a customer doesn't like the dish he ordered, but there's nothing actually wrong with it, I tell the staff that if it's replaced or cancelled the guy goes away thinking we're wonderful,' owner Rupert Chenevix-Trench says.

'The food cost to us is not important compared with the positive, rather than negative, impression. You want him back.'