sign (someone) in
phrasal verb with sign verb uk/saɪn/ us/saɪn/
签到，登记
to sign your name or the name of someone who is visiting you in a book, in order to be allowed to enter a building such as an office or hotel
New security measures require all visitors to sign in at the reception desk and wear a visitor's badge. 新安全措施要求所有访客都在接待处登记并佩戴访客证。