Means they didn't agree with the decision and are allowed to challenge, it's then looked at by the video ref. If successful they keep the challenge. If unsuccessful they lose the challenge and can't make another.
I used to check Rovers results and watch the odd game but I watched more this and last season than others put together
if all rugby league games were like this itd be a huge sport its got everything you want in a sport i dont think this stadium has been this full since wigan athletic were in the prem