When should we flag an answer?

Question

^{I am sorry for a series of questions on this topic recently. This will be the last question I promise :)}

Recently I flagged some answers. The following flags are disputed:

• How to vertically center a table on the page?

  Reason: The answer is seriously lacking information. But... it is accepted.

• Numbers in bold inside a table

  Reason: The answer is clearly wrong, as it is what the OP had tried.

• Increase LaTeX table row height¹ (now deleted by owner)

  Reason: The answer is a duplicate of a competing answer¹.

• Can I create music sheets with LaTeX?

  Reason: The answer has nothing to do with the question. It does load musixtex which is related to music, but I can't find a bit about music inside \begin{document}...\end{document}.

As those flags are disputed, I know I am flagging in a wrong way. But how wrong it is? In what case should we flag an answer?

I am looking for a general answer for the last question above.

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^{1: Only available for users having 10k+ rep.}

Answer 1

Flagging is intended for cases where 'user' actions cannot suffice. For example, an objectively wrong answer can be downvoted: that's how the site is supposed to work. On the other hand, an answer with is about a totally different topic, or is itself a question, should really be removed entirely: that requires moderator action.

I would not get hung up too much on whether your flags are 'helpful'. Some of that can be affected by review queues, etc., and there can be a 'diversity of views'. The helpfulness of flags is mainly there to allow the back-end to order flagged posts for mods: we have a sufficiently-short queue that this is really neither here nor there.