The following are some guidelines for flagging on Ask Ubuntu. These guidelines are derived from existing policies set out in the help center, Ask Ubuntu Meta and Meta SE, and were further refined by a discussion between the current mods.

First, a few general points about flagging:

• As a general rule, if the problem you see with a post can be fixed by editing, then edit and fix it instead of flagging.

• Flags are handled by humans, not machines. This means that similar flags might not always be handled in the same way. While the mod team tries to be consistent, we are still a collection of 12 separate individuals. Your flags can also be handled by any of a dozen or so Stack Exchange employees (yes, SE staff sometimes handle mod flags). This means that your flag could have been handled by any of almost 30 different people. Some discrepancy is unavoidable.

• Flags don't provide you with any reputation. There is no penalty for having a flag rejected. At worst, and only if a significant percentage of your total flags has been rejected, you might get banned from casting flags for a short time. That ban will expire quickly and then you're back to flagging just as before. There is no mark on your record, you can't get banned from the site for mistaken flags and there really, really isn't any reason to get worked up about it. We appreciate the effort that users make in casting flags and they are, when used correctly, a great help to moderators, but they're a tiny, tiny part of what makes Ask Ubuntu great. Let's not get too hung up on them.

Now, on to the specific flags:

1. Not an answer (NaA)

This flag should only be used for answers that are not even attempting to answer the question. The Official SE Policy® on this has been explained very clearly by Shog9 in the main meta here, and is summarized very nicely in this image:

Briefly:

• If the OP is asking how to do foo and an answer explains how to do bar: flag as NaA.
• If the answer contains no valuable information and, instead, only has a link pointing to where an answer can be found, then it is not actually an answer so you should flag as NaA.
• If an answer is a "I'm having this problem too" post, or is otherwise not even attempting to answer the question: flag as NaA

So, NaA flags should only be used if the post is not even trying to answer the question. NaA flags should not be used if:

• The answer is an honest attempt at answering, but is flat out wrong. In such cases, do not flag at all. That's what downvotes are for.
• The question is asking how to do something with one tool and the answer explains how to do it with another tool. This is still answering the basic question (How can I do X?), it is simply providing an alternative approach. Such cases should not be flagged at all.

#2. Very Low Quality (VLQ)

The description of the VLQ flag is actually quite clear (emphasis mine):

This question has severe formatting or content problems. This question is unlikely to be salvageable through editing, and might need to be removed.

VLQ should only be used for things that are so hopelessly awful, they can't be fixed. When thinking about whether you should flag something as VLQ, ask yourself this question: If I could, would I just delete this immediately, or can it be fixed?. If the answer to the question is yes, I would delete this and no it is impossible to fix, then you might want to cast a VLQ flag.

If, however, the post could conceivably be fixed and might contain some useful information, then please do not flag it. Instead, either fix it yourself or, if that's not an option, downvote it.

If the post is just a wrong answer, or isn't using the formatting tools correctly, or has bad grammar or other such fixable issues, please don't flag. Such posts should either be edited into shape or downvoted.

3. Spam

As explained in the flag's description:

Exists only to promote a product or service, does not disclose the author's affiliation.

If an answer (or a question) is being used to sell us something, it should be flagged as spam. 6 spam flags cast on a post will cause the post to be deleted. Spam posts should not be downvoted since that will eventually remove them from the front page and this might prevent enough spam flags being cast to trigger the post's deletion.

It is also important to only use this flag for things that are actually spam. A rant against Ubuntu is not spam. A rude answer is also not spam. If there is no product being peddled, the post is not spam and should not be flagged as such. This is important because the spam flags carry automatic downvotes and can also result in automatic suspensions for the offending user. Also, the posts that are flagged in this way are used to train Stack Exchange's spam filters. So wrong spam flags are actively harmful.

4. Rude or Offensive

This one should be pretty clear. If a post contains rude or offensive language, that's the flag to use. However, these should also be used with care since they, like the spam flags, can lead to automatic suspension of users.

A post that is attacking your favorite software or opinion is not necessarily rude or offensive. This flag should only be used for the truly egregious cases; for posts that contain offensive language, racism, sexism or any other horrible -ism. Not for posts that simply defend a position you happen to disagree with.

Also, if a post contains a couple of bad words but is otherwise fine, just edit the words out instead of flagging. It is much simpler for everyone that way and that’s probably what the mods would have done anyway.

5. "In need of moderator intervention", custom flags.

If you feel the need to flag a post which doesn't fit into any of the categories above, this is the flag to use. However, please make sure to follow the guidelines below:

• Please don't use this flag if one of the others fits.
• If you are sure none of the default reasons applies, take the time to write an informative message explaining what the issue is. For example, if an answer is just repeating information already provided by another answer, please make sure to include this in your message and also include what answer is being duplicated. Custom mod flags along the lines of "this is bad, it should be deleted" are worse than useless since they don't explain why you feel that way.