# Is use of "spoiler" formatting appropriate on this site?

I've seen the spoiler formatting used on other sites where, say, they discuss plot elements of movies and people don't want to give away a key element to someone who hasn't seen the movie and is browsing casually.

It looks like this and requires that you explicitly choose to see the text by click on the "Reveal spoiler" button.

I didn't realize that this was implemented by a generic feature of the markup that is, apparently, available on other sites. I just saw it used in the answer to a homework question here, so I'm wondering what people think about its appropriate use, if any, on physics.

Example answer here: Electric field due to line of charge: A special case

Once seen, I wonder if people will try it more. I'm inclined to think it should be discouraged because I cannot see where it would be legitimately used. Thoughts?

• I have used the spoiler tag on Meta to emphasize that a paragraph was outdated (here). I may have used it once or twice in other contributions. Does searching for >! find usages, or does the search eat the special characters?
– rob Mod
Jul 29 '21 at 17:58
• The answer has been deleted. Jul 30 '21 at 21:15

I don't see a primary use for it on PSE. I can definitely say that it shouldn't be used to hide parts of solutions to homework problems. I guess I understand the intent, but

1. If you're trying to hide solutions from the OP expecting them to work it out first before checking, there is no way to guarantee this will happen. You're essentially still providing a solution; the spoiler doesn't change that. A more effective way to hide solutions is to not provide them at all. And

2. If your answer requires hiding part of a homework solution, chances are the question is off topic and your answer is violating site policy by providing full solutions. If it's a valid homework question that shouldn't be closed, one's answer should focus on the relevant concepts, not on providing a solution.

I suppose outside of this one could find edge cases where a spoiler was effective? I can't think of anything right now though.

• very much an edge case, but I could see spoiler tags being useful for questions about the science behind a recently released TV show or movie where the question or answer contained a spoiler for a major plot point. Aug 3 '21 at 18:45

Maybe it is not a good idea to mention homework or homework-like questions. It immediately triggers a defensive barrier, here on PSE, which prevents people from seeing that such a tool can have interesting uses. The first I see is the possibility of hiding some more formal passage, showing a more discursive first layer of an answer immediately visible and leaving more technical details in the "Reveal spoiler" boxes. I think it could be an interesting feature to try.

• Sorry if my answer gave that impression. I tried to separate that out, and I honestly tried considering the use of spoilers in other situations. I wouldn't say I was triggered by any means. I was addressing the example, not putting up a defensive barrier. Aug 3 '21 at 5:14
• Given my above comment, I think the first part of your answer isn't really helpful here. The example given by the OP is an example where they have seen it been used. Aug 3 '21 at 5:22
• @BioPhysicist my initial comment was not specifically direct to your answer. However, it is my opinion that the real and existing problem of homework questions tends to be somewhat exaggerated, with the result, visible in this question and in your answer, that attention shifts from the possible uses of a neutral feature, to its use for homework questions. I started with that comment not to be polemic, but to make explicit that the example used by the OP could bias the evaluation of the tool. Aug 3 '21 at 5:37
• I think that such a use of a spoiler box would indeed be an effective substitute for the possibility of collapsing parts of the text, as is regularly used for proofs on wikipedia, for instance. It is just unfortunate that it is not possible to customize the "reveal spoiler" caption. Aug 6 '21 at 8:57