My personal opinion is that we are too quick to close questions on this site. Most of the time on closed questions I just think about what the harm is in leaving it open. Sometimes it robs people of the opportunity to answer the question. I'll run across questions that are closed as "too broad" or "off-topic" or "opinion-related" and already have a well-written, complete, factual answer.
As for this specific question, and other regulations questions, it would be nice if the asker specified a country, but they often don't. It would certainly be in order to ask them to specify, but sometimes they don't. Often it is someone new to the site who doesn't realize how different rules can be around the world. And a lot of things are somewhat universal in aviation.
I don't think anyone is expecting a breakdown of 193 nations. The best thing to do is:
- Ask them to specify
- If you can do like Pondlife did, answer for a single jurisdiction and specify in your answer that it only applies there.
- If it's truly unanswerable then vote to close.
If it appears that they're looking for regulatory advice for something flight- related they're planning to do then it would be much more important that they specify the country. But if they're asking about lifting armrests I think giving a country-specific answer or even telling why there might cause a problem is sufficient.
But that's just me.