These posts are generated by member ECU. He is trolling me, both in the main forum and the danger zone, by replying to nearly every post of my mine with these empty/cryptic replies.I think that image was created by someone that agreed/disagreed (probably latter) with someone in the danger zone and somehow it leaked out.
That is the quote feature marking where that person made a post.
Some people post stuff in an attempt to get a response. Then they delete their post Leaving the other's reply hanging.
You'll notice that on many of those, you see no post # or post by that person just above it, because the poster deleted it. Since the marker quote removes their joy of removing their posts, they have reduced their posting that was ruining this site.