qqp question1: If you are a Chinese citizen of the HKSAR and hold a valid Mainland China home return permit (港澳居民來往內地通行證) for how long can you enter and remain in Mainland China? Is there any time limitation at all? question2: If you are a Chinese citizen of the HKSAR and hold a valid Mainland China home return permit (港澳居民來往內地通行證), can you enter Mainland China without it?