Upvote:4
It is linked to the
hold onward or return tickets
part
If you are staying in HK, you need to have onward/return tickets.
If you are in transit to the Mainland of China or the Macao Special Administrative Region, you don't need to hold any return/onward tickets.
Mainland china has a separate border control and they can ask for onward tickets from there. This just means Hong Kong won't be asking onward tickets, if your next destination is mainland china.