I really can't get the point why I was awarded the "quorum" badge. What does the "quorum" badge represent? Any suggestion..
Check out the http://meta.stackoverflow.com/faq , and even in the Stack Overflow FAQ proper it says
The description is pretty clear:
"One post with score of 2 on meta"
where meta is the meta site of that specific Stack Exchange site.
Additionally, there's a silver version of that badge named "Convention" which is defined to be:
"10 posts with score of 2 on meta"