Basketball question

[Tomhusker]

It's been a long while since I have watched ANY basketball, since I absolutely hate it. BUT, I stumbled across the NU game between my trips to the workshop and saw something I am not familiar with. One was that Nebraska actually still has a basketball team.... But:
What is the little horse shoe shaped thingy in the lane under the basket?

 

[sandhill_husker]

That sir is a marker for taking a charge. Anyone trying to plant inside that line can forget about drawing a charge.