Those aren't particularly helpful answers, though they may be about as accurate as mine. I'm sure it's codified here somewhere, but unless someone like Marco is willing to answer the question with a link to the specific criteria, we may never find it on our own.
The reason I answered as I did is that I swear I've seen noobs here that have released odd little template edits and are now labeled as 'coders'. So I just assumed it was automatic. But perhaps they really do have a fixed set of criteria and regular meetings to analyze if those criteria have been met.