I asked this question:

> Popek and Goldberg defined when a CPU architecture is suitable for
> efficient virtualisation.
> 
> I know what to look for to find out if their theorem applies and how.
> But is there a list of CPU architectures somewhere that lists which
> architectures are compliant and which are not (and what instructions
> violate the definition)?
> 
> The Wikipedia article itself lists a few architectures but I am
> looking for something more complete.

And I was told that it is off-topic because "Questions seeking product, service, or learning material recommendations are off-topic because they become outdated quickly and attract opinion-based answers."

However, I don't see why a question about CPU architectures meeting certain technical requirements fits those criteria. I have also found several other questions that likewise ask for lists of CPUs and CPU architectures which for some reason did not seem to be off-topic.

Did the criteria change lately?