Should using a tag epub instead of ebooks restrict the answers a question is asking for?

Question

On Unix&Linux, I am used that questions that have a restrictive tag should only be answered with that restriction in mind, or with a generic answer which encompasses the restriction.

As an example, someone asks: "how do I install Calibre with my package manager" and tags it with ubuntu. In that case an answer that includes the Centos installation program yum is not appropriate, but one using apt-get (the one used on Ubuntu) is. The word Ubuntu does not have to appear in the question¹.

After answering "How can I extract some chapters or sections from an ebook into a new one?"—that doesn't mention any particular ebook format in the text of the question—I answered how to do that for PDF and DjVu.

The OP had already answered himself for EPUB, and I realised later that there was an epub tag on the question. Had I seen this before, I would not have answered for PDF or DjVu ebook file formats, but since the answer was there, and even had an upvote (in addition to a downvote), I thought I ask what the OP had intended, before deciding to delete my answer as inappropriate.

The OP indicated that non-EPUB answers were OK, and in the ensuing comment exchange I pointed out the help on tags. It says:

A tag is a word or phrase that describes the topic of the question. Tags are a means of connecting experts with questions they will be able to answer by sorting questions into specific, well-defined categories.

The help text doesn't mention answers at all, but the OP pointed out that on other SE sites this might be differently interpreted and on meta.stackoverflow.com there seems no definitive support for my, or the OP's reading either.

I am not looking here to be right or wrong, I just would like to use meta.ebooks to discuss this point, so we have a clear reference on how we want this to be handled on this site. This allows us (after the discussion) to (re-)tag consistently if necessary.

As far as I am concerned there is something to say for both approaches, but mixing them on one site is going to be confusing.

¹ _{You will quickly get downvoted on U&L if your answer does not apply because you overlooked a tag}

Answer 1

I agree with your position that tags like epub should generally be seen as restrictive on this site. We have a slew of country-specific tags for exactly that reason, and I can't think of any reason to treat the document-format tags differently.

In practice, however, I don't think there's one answer to this, for the following reason: people asking questions don't use tags consistently. Many users pick tags to draw attention, rather than to limit answers. On some SE sites, that's actually the norm. Even on SO, answers like "don't use [some tool/library/method mentioned in the question] for this" are often appropriate and score highly. So, sometimes, a question is tagged with a restrictive tag, but context indicates the OP is open to answers not relevant to the tag. Other times, the tag isn't there, but the question indicates it should be. These, of course, are reasons why we have re-tagging edits and commenting on posts.

In your case, both your understandings were reasonable, but I think the best approach is to encourage the OP to remove a tag that incorrectly narrows the scope of possible answers. If the OP feels the tag is important, maybe there's a reason for that preference that would make a good edit to the question, such as, "I would prefer answers that deal with the EPUB format, but am open to others, as well."

Answer 2

I was used to the policy on Superuser, the only other website of the network where I have an active participation and some experience about the rules of the community.

There it is allowed, and also encouraged, to (re)tag the questions to also include the relevant answers, like explained on the question linked by Anthon.

So, without thinking much, I did like I was used to.Also, since I posted it in a Q&A format, I knew in advance what tags would be relevant to the answer rather than to the question, so I did it firsthand. If my question is to be retagged, I have no problems about it.

My personal view about it is that tags should be primarily related to questions, but they can be useful also for cataloging relevant answer. In my example, I was giving an answer about epubs, since that forma was my main concern, but I found very useful to have other answers deal with different formats and making the whole question more useful and complete. But I understand that adding tags for every single answer would not be the best solution, considering also the five tags limit.

Maybe a good compromise would be to use tags only for the question itself and for the accepted answer.