TL DR;
The first question I ever asked on SO was about the structure of credit card CVC numbers. Is it always three digits ? Does it ever contain letters ? etc.
(VISA refers to the code as CVV2, MasterCard calls it CVC2, and American Express calls it CID.) - http://www.cybertec.net/cvv.html
I got downvoted, put on hold, and basically reamed by the community. People said I had no business developing web application forms if I don’t understand the rules of validating credit cards, some pretty nasty stuff. I deleted the question, but now I wish I had saved it. We were simply building a form for Braintree, so I just wanted to alert the user ahead of time for validation errors if I could, rather than wait for the API response. I asked my team and a few other developers, the consensus is that it’s always three or four digits, but I still don’t know for sure, I thought this kind of question was the whole point of SO. It took me a few months to get courage to ask another question.
I’ve heard security questions are the most susceptible to getting bad responses. Outside of that, I think SO is still a great resource for very specific questions which have a reproduction on jsbin or codepen. It’s unfortunate that Meteorpad is not currently available, hopefully MDG will host it as a service. That was a great way to describe specific problems and solutions on SO. The forums here are great to describe concepts and general ways to approach problems. I think both systems have their place. If anyone knows about a specification for those CVC numbers… let me know.