I was looking into my flagging history, and discovered that:
Several of my recent flags were marked as "helpful"
This includes 4 questions that I flagged as "not notable", none of which were closed (though one gained a link showing possible notability after a moderator's edit, which presumably may have been as a reaction to the flag).
Yet, most of the posts that I flagged were not actually affected by what I would have expected an action be (closures, VTROs when the flag was to protest a VTC, moderator notice on answer that needs one), though the flag was actually considered valid.
Is there some way to understand what exactly the effect of a helpful flag is? Guidelines?
Sometimes I see actual comments that are responses to a flag (e.g. once I was explicitly told that the flag was correct but question was so old as to make any actions unwarranted, which explains the lack of action on that one flag explicitly). But most flags lack such a comment so I can't tell what the reasoning is.