When do I flag, and which flag do I use?

Question

I can't find anywhere in the FAQ that tells me how to use flags. I'm trying to be a good community member by flagging, and yes, a higher flag-weight does give me a warm fuzzy feeling.

So far, I've been using flags for spam, but I'm not sure when to flag something as "low quality" or "doesn't belong here". Here on meta, some people have suggested that low quality answers deserve close votes instead of flags, but as far as I can see, I don't have that privilege.

Can somebody point me either to answer on meta, or an FAQ page, that shows me when to use which flag and the etiquette involved in flagging.

Answer 1

This is a very useful Q&A: To flag or not to flag and a request for auditing.

I've read a few different answers and tried to pull the info together. So from what I can see, and please correct me where I'm wrong:

Always flag

• Anything offensive ("You would say that because you smell") should always be flagged, wherever. How does the “rude or abusive” flag work?
• Anything that's obvious spam. What are the “spam” and “rude or abusive” (offensive) flags, and how do they work? and is it spamming to link to relevant sections in your own blogspot? and Every post spam?
• Anything illegal - e.g. posts to pirated material

Flagging Questions

When to flag

• The question is impossible to read - either because the English or formatting are so bad. If it's hard - but still possible - to understand try to edit instead of flagging.
• It has absolutely nothing to do with StackOverflow - "What shall I name my cat?" type questions.
• Duplicate questions - only where they are exact duplicates. If you are unsure, it's probably similar but not duplicate, so just post a comment with a link.

When not to flag

• You think the question is silly, but still relevant to SO - "Since I'm only a small website, I don't need to secure inputs, right?". Just downvote it instead of flagging.
• It's on-topic, but there is a more specific SO site - "How do I do this with Wordpress?". You can just leave a comment suggesting that they will get a better and quicker answer on wordpress.stackexchange.com.
• Similar questions - link to the similar question in a comment.

Flagging Answers

When to flag

• Obviously not even an attempt at an answer - "Thanks" or "Yeah, me too".

When not to flag

• A bad answer (i.e. one that you disagree with) - "Security is irrelevant" deserves a downvote and a comment, not a flag
• Doesn't answer the OP's question - "You asked this, but you want this instead." or just "This is a really bad idea and here's a list of reasons why". Downvote and comment if you think it deserves it, but don't flag.
• Answer includes a link with no context, but the link is relevant and not obviously spam. Edit the answer or comment to give the link context. Are answers that just contain links elsewhere really "good answers"?

Flagging comments

How does comment voting and flagging work?

When to flag

• Obviously spam or offensive

When not to flag

• 'Me too' and 'thanks' type comments and mostly irrelevant comments - SO automatically hides them anyway. There are bigger fish to fry.
• Comments that would be better as an answer - just suggest the commenter moves it to an answer instead without flagging
• Every comment in a conversation - just flag the first one, and leave the mod to read the rest Add possibility to remove comment noise (fancy edition)

Answer 2

You can find a few posts about how flagging works in the FAQ for StackExchange Sites under the "Moderation" section.