Husband is HK resident working in Shanghai want to apply for S1 Visa

Hi, my husband moved to Shanghai for work in July last year. I am going to move to China in April and think S1 type is appropriate for my situation. Does anybody know what kind of document that can prove he's been living there for more than 6 months? He only has return home permit and working permit, but none of that can prove that he has lived in Shanghai for 6month+. I think the temporary residence permit for HK resident has been discontinued... Can someone please help? Thanks