For example I submitted PDF here: https://news.ycombinator.com/item?id=34757769 but was flagged after while (and discussed as well). But I'm not sure why? Was it too political? Was it because of source from dropbox?
I don't want to relate my question for this specific example. Just a suggestion to explaining flagging.
Please don't complain that a submission is inappropriate. If a story is spam or off-topic, flag it. Don't feed egregious comments by replying; flag them instead. If you flag, please don't also comment that you did.