72 hrs visa free for beijing

i read from some website they say that : Foreign airlines must contact Beijing Entry Frontier General Office to apply for 72 hours free transit visa for their passengers. do we still need to do this step? does all airline know about this? or just inform the check-in counter staff that we are going to beijing (FRA-BJS) applying for this free transit visa? and some website also say : Travelers must register with police within 24 hours of arrival . means i have to do to the police station to report? can someone please help me with this thank you very much.