Checking in for pre-RP ADR"S

Ok -I have a pre-RD appointment for BBB, I know they will let me into MK early, BUT how do they check? Do Cast members Scan Magic Bands or do I need to print a copy of reservation? Same question for pre-RD at CRT- How is verification done? Thanks!!!

THey had a clip board with reservation names on it last time I went to one at Akershus in October. Don’t remember having to even show ID.

A CM near the entrance to MK had a clip board with a list of names with reservations 2 weeks ago for pre-RD CP.