Corner-flagging is the act of taking the ball into the corner to waste time.
The player in question dribbles the ball into the corner of the pitch and hunches over it while frustrated opposition players desperately try and hack round his body.
When performed by the opposition it is a gross act of bad sportsmanship, when performed by your team it is just a part of the modern game and some good professionalism.
Notable instances of corner-flagging
Greece were able to win Euro 2004 by corner-flagging for over 800 minutes. While the Greeks celebrated an unlikely and historic triumph, many felt it was something of shame that a team could win one of football's showpiece events having barely mustered a shot on target. Some even believed it made a mockery of the game.