I've been struggling with a very interesting puzzle today, only to find out that the answer is very country-based, meaning that I, not being in the same country/culture of the OP, could not resolve it or at least start severely disadvantaged.
This has already happened before, but sometimes the issue is clearly stated in the question.
How can we deal with it? Should the OP state it clearly or not? Should we create an apposite tag like country-based or similar?
To add some thinking: a big distinction has to be made between language, for instance idioms or puns, and culture, for example which kind of sentence is said during the festival that Osaka throws the first of july.
I think that the first is avoidable but not dangerous, a non native english speaker is disadvantaged but still can answer the question.
In the other hand, the latter, should be completely avoided or clearly stated. If I make a riddle about the type of pizzas sold in Naples I narrow too much the audience. The problem is that if I don't state that I'm talking about the Naples' pizzas, answers could involve Pizza Hut or the question will ask the users to find an answer that they can't find.
How or what defines the difference?