ive seen these in some (not all) of the courts ive been to and just noticed them in the olympics as well what do they mean (if anything)? thanks!
For testing the speed of the shuttle. When they hit from the outside of the other side, it should fall between these 2 lines! Thats why it is there....
What the above poster said is correct. You stand behind the last lines of the court and you hit a shuttle (with a medium arc so not to flat and not too high) so that the shuttle should land near those two lines. It's a rough estimate, I've seen shuttles fall a bit short but the referees will say no tipping allowed (at lower level tournaments)
The shuttle MUST land within those lines otherwise it is NOT appropriate. If the umpire says no tipping then request the tournament referee and demand correct speed shuttles are supplied. Playing with a shuttle that is too slow can increase the chance of injury as you have to hit everything 'too hard'.
I have seen shuttles get close but still fall short of those lines and the referee can still make a decision of do not tip. I speak about this from experience.