The majority of answer I can find to "I've been serially downvoted, what should I do?" advise users to flag one of their posts and mention the voting anomaly.
Except I did this, in response to a relatively small run of down-votes which were never reversed, and the flag was declined:
Apr 30 at 16:28 declined - flags should only be used to make moderators aware of content that requires their intervention
Perhaps there wasn't enough down-voting to warrant a flag, or I had flagged it to soon, or it was an incredibly unlikely coincidence and not serial down-voting at all. This all seems largely irrelevant to what actually troubles me: The moderator explicitly told me that I was misusing flags. This runs directly counter to (what appears to be) the consensus on meta, that this is a valid use of flag-for-attention, and the correct way for users to address serial down-voting.
Given that this question comes up so frequently, I'm wondering, both for the sake of users and moderators, if we can clarify the real, officially endorsed policy for bringing this sort of thing to the attention of moderators.
This is not about my rep or a specific instance of downvoting on my account.
The top-voted answer, by a diamond moderator, advises:
Flag one of your own questions and explain the situation. It doesn't matter which question you actually flag, but it will make it a bit easier on the mods if you flag one of the questions which is in question.
This FAQ answer, under What if I think I'm the victim of voting fraud?, first tells us to do nothing, and then tells us:
If the 24 hours has already passed and you don't feel like waiting in chat, you can then flag one of your posts and explain what happened so a moderator can look into it or post a new question on meta to get feedback and explanations.