Complex sentence: Conversely, Chinese citizens residing in these regions cannot use their SAR passports or Republic of China passports to enter mainland China, instead using the Home Return Permit or the Mainland Travel Permit for Taiwan Residents as a travel document.
Split into simpler sentences: Conversely, Chinese citizens residing in these regions cannot use their SAR passports or Republic of China passports to enter mainland China. Instead, they must use the Home Return Permit or the Mainland Travel Permit for Taiwan Residents as a travel document.