China is an ICAO member state and HK is included as a result, although it has it's own Civil Aviation Department. Hong Kong is not a country, it is a Special Administrative Region of the People's Republic of China. HK will issue licences on the basis of a pilot's home licence. These are not endorsements, they are full licences. However, very few agencies will issue a licence based on the HK converted licence, so it's important to keep your home licence current.
Another issue is that the HK CAD are so far behind the times, other agencies will not recognise HK CAD initial issue licences for conversion.
Taiwan is not an ICAO member state due to the protests of the PRC.