Frequently it is useful to reference codes and standards in either questions or answers. However, many (if not most) codes are copyrighted and should be purchased from the responsible entities. How acceptable is it to quote directly from codes here?
Knowing full well that none of us are lawyers, I went over to law.SE and found this answer on fair-use. It basically lists four "factors" usually considered in US law* when judging the validity of fair-use:
- Purpose and character of use - criticism, comment and teaching are explicitly considered fair-use.
- The nature of the copyrighted work - factual information can more easily be considered fair-use
- Amount and substantiality of the portion used in relation to the copyrighted work as a whole - the larger the excerpt, the larger the risk to a fair-use argument. However, one must also consider the significance of the excerpt being copied: if it is "the heart" of the work, it may not be open to fair-use.
- Effect of the use upon the potential market for or value of the copyrighted work - if the fair-use would reduce the market value of the original work, that weighs against fair-use.
Factors 1 and 2 certainly work in our favor: this is a site which deals with, among other things, teaching, commenting and occasionally criticising codes of factual information.
Factors 3 and 4 I'm more ambiguous about. No single question or answer will quote an entire code, but over time it's entirely possible that the site as a whole will quote a significant fraction of the standard. If one were to compile all the citations the excerpt could be considered substantial according to Factor 3. And if people can just come over here to read up on "any" portion of the relevant code instead of purchasing it, that'd certainly reduce the potential market for the original work.
* While the US isn't the only theoretically relevant jurisdiction, it's probably the most relevant.