Suppose a question does not specify a specific jurisdiction.
An answer is posted that begins with "In the US, it works like this: ..."
If I know that the answer is exactly right in some other jurisdiction, say the UK, should I do something, perhaps add a comment with "This answer is also true in the UK," should I add it as another answer or should I merely upvote that answer without adding the additional jurisdiction?
Let's say that the question is like this one. It doesn't specify a jurisdiction, though it recommends the United Kingdom. If Hypothetical Answer A talks about, say, Germany, and you have some information about Italy, then perhaps a new answer would be warranted - if the laws are different enough. If the laws themselves are almost identical, then a comment could be just enough. However, if there are analogous laws in both countries, but they have different implications, then I think a new answer is warranted.
There's always that grey area of subjectivity, but most of the time, you should be able to figure out what the similarities warrant.
Both a comment and an answer can be helpful. But if you have a lot of new information because the law is so different, then an answer is probably warranted. There's nothing inherently wrong about just posting a comment, though - you're contributing helpful information.
You can also ask about a specific case in chat.
In short: Good.
Such a comment expands the information in the answer to make it more useful, especially to people who might find that answer while they are wondering about the jurisdiction referred to in the comment.
See also answer/discussion here about value of answers (incl. comments on answers) making it clear what jurisdiction the answers apply to.
If the question needs (but does not provide) a jurisdiction, the users answering these questions should not be guessing what will help that author specifically. It is inadvisable to just start listing all the possible iterations as separate answers and have the voting mean anything. Try not to turn this into a guessing game. If the author has not made it clear what they are asking, ask for clarification or put the question on hold as unclear until that information can be provided.
But if the question was well-asked and well-answered, oftentimes someone wants to know <variation on that problem> applies their new situation, too.
Unfortunately, answering questions in comments is troublesome at best. Comments do not have the same capabilities of vetting and voting for a proper answer. If you are answering questions in comments, you are doing it wrong. Please do not use comments to answer questions. Stack Exchange was specifically designed to avoid all the forum/chat-room problems of posting information however and wherever you like. Going off on these comment-discussion tangents is not how we curate content. If answers start appearing in comments, they will likely be removed. Please ask a separate question.
