Re-encoding group > ... What gives?

Hey there. Hope some of you guys can help me "solve" this non-issue that's boosting my undiagnosed OCD :

So the thing is, when I fire up a video on Media Player Classic, I occasionally get a message on the lower part of the screen. White text on top of the video, broken in two: "Re-encoding group", then "--- BoB - Best of Both ---". It only happens for the first video I play on any given session, and it doesn't bother me all that much, but I'd like to know what on earth it means and how to turn off that notification if possible. I don't really care much about codecs' inner workings as long as they work as intended, so I'd rather keep notifications to a minimum. Can any of you guys enlighten me?

That is a subtitle. It was added by the creators (encoders) of that specific video file. It should appear each time you play that same file.

For a minute there, I felt very stupid... But nope, that's not it, it would happen only for the first video I played on a given session, no matter which, and the font was different from the one the video's subtitles were using (it would even appear on top of them). I'm saying "would" because, apparently, it's not happening anymore . So I guess I'd still like to know what it was, but it's become even less pressing...

It was made by these people:
http://bobrelease.blogspot.com/‎

Too plausible to keep arguing, I guess. Still weird that I'd only get the overlay at random-ish times, but I think my OCD is appeased for now. Thanks a lot .