confused about entry permit requirements

Hello,

I am trying to plan a trip to China, Hong Kong, and Macau in March, and am slightly confused as to the visa requirements.

Right now, it looks like we will arrive in Shanghai (PVG) and then directly go onto Hong Kong without leaving the airport. However, this might change, and we might stay the night in Shanghai. When we return to the US, we are probably going to fly from Hong Kong to Shanghai again, and stay in Shanghai for a night or two, but less than 72 hours, before returning to the US (see draft itinerary below).

From what I understand, this would NOT require a full entry permit, only a travel type. Is this correct? Do we need to apply for this beforehand? We are trying to book this soon, so we would very much appreciate your assistance. Thank you,

Tom Fitzgerald

12 March: LAX - PVG
12 March: PVG - HKG
19 March: HKG - PVG
21 March: PVG - DTW