Steve - flagging posts/comments buries them from view and perhaps a feed.
Someone with more (or a lot) of Steem Power and Reputation than you - can affect that.
I was joking today about my post being flagged, well mostly -- you just never know.
- ways you can view a flag (likely more)
--- but on the top of a post you can see if it has flags or not -- same with comments - look up and on the right.
-- take your mouse on a post or comment and hover over the "votes" area -- downvotes currently show up as flags and I think always show at the top of the list -- as do the whales votes I think -- who have the most power on voting.
-- you can also check votes on the blockchain by looking -- for ex. -- steemd.com/stevesmith -- for your account - that is one solid way, there are others too. Hope that helps.