What are the bounds of plagiarism when considering a suggested edit?

For example, I've just rejected an edit to , because the text was lifted directly from the Wikipedia page of the same topic, without citation.

How do we know what sources can be lifted without citation, or with citation, or not at all?

  • 1
    I've cleaned it up a bit, and cited the Wikipedia article.
    – user102937
    Dec 1, 2011 at 17:39
  • I'm curious what counts as a citation too. Does "see this Wikipedia article for more info" count, or does it have to say that the text was taken from Wikipedia? Jul 26, 2012 at 14:03
  • 3
    @MichaelMrozek 50-rep bounty? Cheapskate.
    – Pops
    Jul 26, 2012 at 15:04
  • 1
    @PopularDemand Well, most of my bounties don't do anything, so I don't feel the need to spend more. For example, the one that's ending today with zero new activity Jul 26, 2012 at 15:21

2 Answers 2


In most countries, United States included, you may by default not use content created by others without their permission (this is called copyright). The details may vary between countries but that is the default starting point for all copycat discussions.

Content on both Stack Overflow and Wikipedia is licensed with Creative Commons Attribution-ShareAlike 3.0 Unported. This allows copying and modification by others, even for commercial use, as long as all copies keep the same license and specify the source. You may therefore freely copy text from Wikipedia as long as you include a link back to the article.

Other sources than Wikipedia may be more troublesome. Large text blocks may not be copied due to the "deny by default" nature of copyright laws. The easiest thing is usually to ask the original author of the text for permission, and that permission should include the rights to adapt and share the work under the Creative Commons license mentioned above. The Stack Exchange interface does unfortunately not provide fields to include information about such permissions so in some cases you may just choose to rewrite the text yourself.

Most countries, however, allows text quotations (covered in the U.S. by the broader term fair use). This should usually be small parts of text (maybe one or two sentences) and clearly laid out as citations with quotation marks and source info.


  • All copied content must always have a link or other clear source information.
  • Content which is not licensed as Creative Commons Attribution-ShareAlike 3.0 Unported must be quotations (use quotation marks!) and not too long (generally only a couple of sentences).
  • This applies even if no copyright © symbol is visible at the original location.
  • It also applies to content without a clearly specified author.

Anything which does not follow these guidelines should be either rejected or improved to include the correct source info.

Some useful resources:

  • 1
    +1: Really good info. Is it easy to spot straight copies, other than just grabbing a sample and searching for it as a quote in Google? Jul 26, 2012 at 21:02
  • Jon, I usually spot copies pretty easily. Copies are often either from a library's homepage or from the first Wikipedia paragraph. The homepages are often trying to "sell" their library so they sound pretty selling, not always that descriptive about what the library actually does. Wikipedia articles have a certain style to their writing, especially in the first sentence. Aug 17, 2012 at 15:49
  • 3
    I think it's worth emphasizing that plagiarism is not defined by what copyright law requires; we have additional requirements. The question asks about plagiarism. Copyright law does not define what constitutes plagiarism. Copying a substantial portion of the text without attribution is plagiarism -- even if it is allowed by copyright law.
    – D.W.
    Sep 3, 2015 at 17:16

Wikipedia has a page where you can cite any page in a number of formats: Special:Cite

Here's their page on Citing Wikipedia. Just enter the title of the page in the Special:Cite tool and it will generate citations in many formats - like APA, MLA, and Chicago. Here's the C++ page, cited in APA format, generated from that tool:

C++. (2012, July 24). In Wikipedia, The Free Encyclopedia. Retrieved 14:12, July 26, 2012, from http://en.wikipedia.org/w/index.php?title=C%2B%2B&oldid=503988131

Just use that citation (any format is probably fine for SE) when using Wikipedia in a tag wiki (or even a post).

  • Handy. So does the citation have to be in that format? Jul 26, 2012 at 14:17
  • 1
    @MichaelMrozek not really, it's just an easy way to make an extremely clear citation. As long as you attribute the content directly to the source it should be fine by Wikipedia's license. Plus the link to the specific revision can be handy if the content changes
    – Ben Brocka
    Jul 26, 2012 at 14:20
  • I don't think a cite format is really necessary. That's for print publications. A link back to the original Wikipedia article should more than suffice.
    – ale
    Jul 26, 2012 at 16:04
  • 1
    This covers wikipedia, but not other sources - is there a general guideline, or should all sources be cited irrespective? Jul 26, 2012 at 16:28

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .