Recently I came across a question that in order to answer accurately would have required using a substantial amount of technical information which is copyrighted. There is an official website for such information and that website also is copyrighted.

Now the question was good and there was a valid answer, but that answer was to the effect of "Please see the official website because due to copyright restrictions we cannot provide the details on Stack Exchange." That answer was voted down.

Are we forbidden from providing the best and only possible answer if that answer is just a link? I am not talking about linking to an illegal copy, but rather linking to a legal (official) source of copyrighted information which Stack Exchange cannot legally replicate on-site.

While I am trying to keep this Question at the generalized policy level, the question I'm referring to asks for a formula. The answer requires replicating an extensive set of data tables located across several pages of a website, where every page bears a copyright notice. I linked to that website, but my answer was deleted. There's another answer that I think is worse than mine; it was accepted, while mine was deleted.

  • Related/dupe: meta.stackexchange.com/questions/49427/…. Jun 27, 2016 at 13:15
  • One more related thought ... If a question is a good one, it is not right to call the question "off-topic" yet if we cannot answer it legally on-site is the question valid for posting on Stack-Exchange? If it is good/on-topic and yet invalid and we then remove it won't the question just get asked again and again?
    – O.M.Y.
    Jun 27, 2016 at 13:16
  • @ShadowWizard -- not the same question. That is about linking to illegal copyrighted material. I am talking about linking to legal material (official sources) that cannot be copied onto Stack Exchange.
    – O.M.Y.
    Jun 27, 2016 at 13:18
  • Sure @D.W., but let me summarize because this question ended up with a long chat thread. The question asks specifically for a formula to calculate QR code capacities. The answer requires replicating an extensive set of data tables located across several pages of the [website](qrcode.com) of the QR Code inventor, every page bears a copyright notice. The full details for implementing QR Code is patented and is sold as a copyrighted document through the ISO website. That said, you can read the question at stackoverflow.com/questions/14908842
    – O.M.Y.
    Jun 28, 2016 at 10:35
  • Unfortunately MY answer to the question was deleted 4 hours ago it seems. The chat however seems to have survived the purge: chat.stackoverflow.com/rooms/115740/…
    – O.M.Y.
    Jun 28, 2016 at 10:37

2 Answers 2


Your premise is faulty. Such a question can be answered without violating Stack Exchange rules against link-only answers, and without violating copyright rules.

I suspect you misunderstand how copyright works. Copyright does not prevent you from paraphrasing or explaining in your own words. And, copyright does not protect facts. Copyright protects the specific manner in which ideas are expressed, but not the ideas themselves: copyright may prevent you from copy-pasting or re-using their words and may protect the particular choice of phrasing selected by the author, but it doesn't prevent you from using or describing the ideas or facts themselves.

So go ahead and link to the external site, but also provide a summary of the main ideas there. Make sure your answer will be useful even if the link stops working.

For example, a formula is a fact. There's no protection for mere facts. Don't copy-paste a table of formulas from an external site, but you're welcome to re-derive the formulas and show the final result you got. Nothing prevents you from writing an answer that shows how to derive those formulas, re-derives the formulas yourself and shows what you came up with, and/or summarizes the formulas and their implications.

Don't forget to follow Stack Exchange's rules about how to reference material written by others, including providing proper attribution.

  • Since my answer was deleted allow me to post a small excerpt of part of my answer which explained why an answer was not possible. The next comment provides context for the complexity of the answer to the OP's question:
    – O.M.Y.
    Jun 28, 2016 at 10:57
  • EXCERPT (see above comment): "There are 6 major formats of QR code: Model 1, Model 2, Micro, iQR, SQRC, and Frame QR incorporating up to 61 density levels (called "versions"), 4 encoding formats (number, alphanumeric, binary, and kanji), 5 error-correction protocols (L, M, Q, H, and S), and 2 different matrix layout formats (square and rectangular) Plus the option of multiple concatenated matrices, each of which affects information capacity."
    – O.M.Y.
    Jun 28, 2016 at 10:58

Well, that's a delicate matter since usually link only answers are frowned upon.

However, if all the following criteria are met, I believe this would be OK to post the answer:

  1. The question is really on topic on the site, and...
  2. It's really illegal to quote the relevant parts from the source, and...
  3. The source is both official and "stable", meaning not some privately held website that can shut down any day.

In the answer, try to explain as best as possible without quoting, and mention that the source is copy righted this it's not possible to really quote the relevant parts.

  • In the question I worked on the source was the inventor of the technology and the website was his website which also is the company that licenses the technology. The specifications covered a number of pages and there was no way to answer the question without using a substantial portion of the material on those pages.
    – O.M.Y.
    Jun 27, 2016 at 13:29
  • @O.M.Y. still, what about such an answer? "As explained here, you need to do [this and that], for more details visit the site, I can't post relevant parts here due to copyright issues". Usually such answers will be flagged and deleted, true, but I want to believe that under those special circumstances it will stay. Of course, I might be wrong, better wait for official answer before going and posting, it's just that many times official answers takes 6-8 days/weeks/months to be given here. Jun 27, 2016 at 13:31
  • The answer I provided was multiple downvoted and has even been recommended for deletion, in which case future readers of the question will not know of these issues and half-accurate answers will rise to the top. I think we need a policy that allows such answers as rare exceptions.
    – O.M.Y.
    Jun 27, 2016 at 13:33
  • @O.M.Y. true, given official answer here, you'll be able to link to it in your own answer that would be otherwise deleted. Jun 27, 2016 at 13:34
  • The question was for a formula to calculate the way something worked in software. The answer was based on extensive tables of data that were proprietary knowledge that was available but not copyright free.
    – O.M.Y.
    Jun 27, 2016 at 13:35
  • Well if it takes that long then I might as well get started. :)
    – O.M.Y.
    Jun 27, 2016 at 13:37
  • Is there a procedure I need to follow for trying to add a new SE policy?
    – O.M.Y.
    Jun 27, 2016 at 13:39
  • @O.M.Y. yes, posting here in MSE. Like I said, once SE employee will post an answer, it will become official aka new policy that you can link to, e.g. in custom flag on your answer if it's deleted, then a moderator can undelete. Jun 27, 2016 at 13:41
  • I don't care so much about the one question as much as I care about the fact that there are questions like this that will (and probably already have) pop up from time to time and we need a policy to deal with them whenever it happens.
    – O.M.Y.
    Jun 27, 2016 at 13:53

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