Maybe its the only thing they had readily available. Perhaps they could adjust the text to 'GM adjustment' so that it can be used for +/- ambigously
but at least is it confusing, i nearly write a post to the gm till i realised that it wasn't a fine and i got money ;) And one of the german Gm had 17 post like this, around 9am in germany.
Maybe they also could create a new line, normally that should be possible.