Seven Deadly English Shibboleths

There are, however, seven words that the English uppers and upper-middles regard as infallible shibboleths. Utter any one of these 'seven deadly sins' in the presence of these higher classes, and their on-board class radar devices will start bleeping and flashing ...

• Pardon ...
• Toilet ...
• Serviette A 'serviette' is what the inhabitants of Pardonia call a napkin. This is another example of a 'genteelism', in this case a misguided attempt to enhance one's status by using a fancy French word rather than a plain old English one. It has been suggested that 'serviette' was taken up by squeamish lower-middles who found 'napkin' a bit too close to 'nappy', and wanted something that sounded a bit more refined. Whatever its origins, 'serviette' is now regarded as irredeemably lower class. Upper-middle and upper-class mothers get very upset when their children learn to say 'serviette' from well-meaning lower-class nannies, and have to be painstakingly retrained to say 'napkin'.
• Dinner ...
• Settee ...
• Lounge And what do they call the room in which the settee/sofa is to be found? Settees are found in 'lounges' or 'living rooms', sofas in 'sitting rooms' or 'drawing rooms'. 'Drawing room' (short for 'withdrawing room') used to be the only 'correct' term, but many upper-middles and uppers I feel it is bit silly and pretentious to call, say, a small room in an ordinary terraced house the 'drawing room', so 'sitting room' has become acceptable. You may occasionally hear an upper-middle-class person say 'living room', although this is frowned upon, but only middle-middles and below say 'lounge'. This is a particularly useful word for spotting middle-middle social climbers trying to pass as upper-middle: they may have learnt not to say 'pardon' and 'toilet', but they are often not aware that 'lounge' is also a deadly sin.
• Sweet ...

SOURCE: Watching the English: The Hidden Rules of English Behavior, by Kate Fox (Hodder, 2004), pp. pp. 76-78