It's perfectly simple clutch. It's not black and white it's just context.
"when in Rome..."
Consequently one tries to speak french in france, one doesn't go around bare-armed or bare-legged in some Moslem countries, one covers one's head in Greek churches, one doesn't show anyone the soles of one's feet in Thailand, one remains silent during kicks at Thomond Park, etc, etc...
Its about not causing offense when in someone else's house....
EP however is more complex and ambiguous, some do silence when we're winning, or easily losing, noisy if we feel aggrieved, if the ref has made a mistake or if it's down to the last kick of the match and we're facing a crucial loss......
i.e there is no real concensus but everyone has their own individual sense of what is right and they follow that...
