As there are many complaints about uncertainty of which flag to use for what post and even conflicting feedbacks from different moderators or established users, I want to create some kind of official flagging checklist / decision helper / cheat sheet which can be followed by all flaggers and reviewers to reduce confusion and incorrect usage.

In your answer, please treat the available flags for questions and answers separately. You have to list what conditions must be met to make this type of flag applicable to a post (specify "all of these conditions", "at least one of these conditions" or "none of these conditions" if necessary)

Please note that I am looking for official statements with this question, not personal opinions!