I know this is a newbie question, and most likely a duplicate, but for some reason can find it. Were do I find the explanations about flags, what they are in one compact place. I resonantly flagged a comment as offensive, but it was declined. Latter I discovered that the definition of offensive is something other than I thought. Although the comment was clearly offensive towards me it was not offensive in the definition of the flag so I was incorrect to flag it as such. So yes, to avoid it in the future:
Where can I find the definition and usage of all the flags?