You question, while on-topic, is not *definitively* answerable. TL;DR: To put it plainly your question does not fit in the simple question and answer paradigm. > ... is there a list of CPU architectures somewhere that lists which architectures are compliant and which are not (and what instructions violate the definition)? You were essentially asking for someone to provide a list (or even a list of lists) of resources. That is, in no uncertain terms, a learning material recommendation. Even if such a list exists and is currently up to date it would be out of date next week. If the question were to be make "Post a list here, on this site, that meets these criteria" then it would be too broad. There could be a thousand answers. But, and this was the crux of the matter for me, you could never choose the undeniably (verifiable by the larger community) correct answer. One person could post a list that gives a more complete (copy-paste) list of architectures but another person posts an abridged list that only lists a few architectures and a small subset of instructions that violate your definition. *Which of those two answers would you mark as correct?* The same goes for "give me a link to a website that does X". One may be a better list, another might have a thorough examination of a smaller list, another site may be a balance of the two. Which site would be the correct answer in your case? Maybe it's none of them, maybe all three. *How would you award the "correct" answer?* I would have to say that you simply cannot. To quote [What types of questions should I avoid asking?](http://superuser.com/help/dont-ask): > You should only ask practical, **answerable** questions based on actual problems that you face. Chatty, open-ended questions diminish the usefulness of our site and push other questions off the front page. >**Your questions should be reasonably scoped**. If you can imagine an entire book that answers your question, you’re asking too much. Your question might be answerable, but there is no way to determine if one answer is more "correct" than any other answer.