Do not make a noise during a rally. Do not applaud a net cord or a double fault. Do not remove your shirt at any time.
The polite instructions to spectators in the Wimbledon daily program speak volumes - this is all about England's genteel middle class performing their traditional summer rituals. One is expected to keep the stiff upper lip firmly in position.
It is all a far cry from the other grand slam tournaments.
Imagine what it would be like issuing such instructions to passionate Parisians cheering on their local heroes or to raucous New Yorkers and ebullient Aussies bellowing their support.
"We have set out to re-create a tennis match in an English country garden. The gentility is half the charm of Wimbledon - but in a modern setting," Wimbledon spokesman Johnny Perkins explained as the tournament began on Monday.
Even the Wimbledon hecklers are a pale shadow of the booing and booming brigades elsewhere.
For two weeks every year, British sports fans yearn for a first Wimbledon men's singles champion since Fred Perry in 1936.
In recent times, Tim Henman came close but never beyond the semi-finals. Now it is the turn of Andy Murray to have the weight of a nation's expectations on his shoulders.
Cue the Centre Court hecklers, who inevitably shout out "Come on Tim" in any Murray match, buoyed by the response when the ironic cheer is met with a polite laugh every time.
Umpires are also greeted with a titter when they get the latest 'ova' or 'eva' from Eastern Europe muddled up when they are confronted with just too many syllables in a tongue twister of a name.
Even the club's name dating back to 1877 - The All England Croquet and Lawn Tennis Club - conjures up elegant images of crinolined Victorian ladies reaching for their croquet mallets, while the gentlemen resplendent in flannelled white trousers take to the grass, clutching their wooden racquets.
Wimbledon's gleaming roof cover on Centre Court guarantees privileged ticketholders a day of uninterrupted play, but fans on outside courts so often have to face the perennial curse of rain delays.
Stoic spectators take shelter for a plate of extravagantly priced strawberries and cream washed down with a nice cup of tea. It is a microcosm of the British at play - whatever the weather.
Perkins agreed: "It's a mixture of history and tradition flavored with a cocktail glass of Pimms or that inevitable cup of tea. And even when it's raining, we keep calm and carry on."