This is London: London 2012 will be a new experience for one volunteer. Urvasi Naidu, who has been a volunteer for every Olympics since the 2002 Salt Lake City Games, always carries some masking tape in her handbag.
"What I am usually looking out for," says Urvais, a lawyer by profession, "are groups of people wearing T-shirts advertising rival products to the official sponsors. If they are, I first try to get them to wear the T-shirts inside out. If that doesn't work, I use masking tape to cover up the advertisement so it's not visible on television."
It may seem extreme but Urvasi, who has contributed to a book on the subject, says: "Sponsors pay a lot of money, they have a right to protect their investment - other brands are not entitled to advertise. When you buy an Olympic ticket you are entering into a contract with the organizing committee. If you look at the website, the conditions are all spelt out."
Clause 19.2.3 states that prohibited items are "objects bearing trademarks or other kinds of promotional signs or messages (such as hats, T-shirts, bags) which Locog [the London Organising Committee] believes are for promotional purposes".
However, the story of the masking tape is only one example of how London will change dramatically to welcome the world next year. At several hotels, particularly the so-called "Olympic family" ones, such as London's Hiltons and InterContinentals, as well as the Dorchester, where the top officials will be staying, Perrier, a rival product of official sponsor Coca-Cola, will not be served - customers will get Coke's bottled water, Schweppes Abbey Well, instead.
It is all part of making London a "clean city" and ensuring that sponsors get their money's worth.
Sport as business is hardly new. All major events have brand protection units to ensure sponsors are not ambushed by rivals seeking to latch on to the event without paying. Those who have bought Olympic tickets already know that the only credit card they could use was Visa, a major Olympic sponsor. Visa will also be the only card accepted at all Olympic venues.
Many other sporting bodies are proud to boast that they have got into bed with Mammon, but while the Olympic organizers need the money, they do not like to be seen consorting with it.
Winning athletes don't get a cheque, they get a medal; the athletes' clothes will carry limited sponsor advertisements and the venues will have none at all. It's nothing like Test cricket, where even umpires wear advertising, or Champions' League matches, where adverts on the sidelines change during the match as if to reflect the fluctuating fortunes of the two teams.
For Sir Craig Reedie, the Scot who sits on the all-powerful International Olympic Committee executive board, this is part of the unique Olympic experience. "We want an uncluttered view for the spectator or the viewer at home, nothing else but the performance of the athlete, nothing that would distract."
However, this Corinthian façade is only possible because the Olympic sponsors have free scope to advertise in the vicinity of the venues with no fear of competing advertisements - the essence of a clean city.
McDonald's is a main Olympic sponsor, so it is only its food that will be served at London 2012 venues - with one exception: Wimbledon will still have strawberries and cream as McDonald's has not taken up the rights. And, if previous Olympics are any guide, the sponsors will also make use of sporting icons. In Beijing, this led to a hilarious moment when nine-times gold medallist Carl Lewis, interviewed in a McDonald's restaurant, was asked what athletes could do about drugs. He kept repeating: "Eat French fries!"
London will not be just "cleaned up" but dressed up too, with a special Olympic look.
Reedie says: "In the host city contract that London signed, it guaranteed to control advertising across the city. The organising committee gets control of the sites and makes them available to the sponsors. London has been doing the same." In the past few months Locog has been booking billboard space and, if it is not taken up by sponsors, then it may be made available to charities.
Spectators are meant to experience the Olympic "feeling" all the way to the venues, with most of the advertisements they see being those of Olympic sponsors. Wimbledon will have to cover up its Rolex adverts and the O2 will be temporarily renamed the North Greenwich Arena, as BT is an Olympic sponsor.
Reedie says: "Of course, not all billboards are affected, not the permanent ones in Piccadilly Circus. Do not forget the clean city look we insist on can improve a city. Take Athens, for instance. Before the Olympics the city was disfigured with too many billboards - some of them illegal. We got the authorities to take some of them down, with the result that the entire look of the city was transformed - we left Athens a better looking place."
The IOC's clean-city concept was developed after the 1996 Atlanta Games. "The Atlanta Olympics," recalls Reedie, "provided us with clean stadiums but, within a few yards, they had street vendors selling rubbish: T-shirts, memorabilia and pins. It was like a bazaar and it ruined the Olympic experience."
One major problem for the London organizers is that the moment you land at Heathrow you see advertisements for HSBC, a rival of Lloyds TSB, which is a major 2012 sponsor. The organizers realize they cannot take those advertisements down but they are working with BAA to make sure there are advertisements for Olympic sponsors at London airports. And enough of the many billboards on the way into town will carry reminders of who funds the Olympics.
The IOC may present the Olympics as the last bastion of amateurism but next year Londoners will be in no doubt about the serious money driving the Games.