In movie's crew names, there is a C.A.S after a name. When I searched for it, I get Chemical Abstracts Service. I think it's not the meaning of this. What does C.A.S mean?
If you're sure it's CAS, that's for sound production, members of the Cinema Audio Society.
The Cinema Audio Society was formed in 1964 for the purpose of sharing information with Sound Professionals in the Motion Picture and Television Industry. We have seven (7) categories of membership: Active (Full), Associate, Career Achievement, Honorary, Student, Retired and Corporate Members.
Active Members are Mixers (Production and Post Production, Film and Video) who work on Feature Films, Television, and Commercials, as well as Mixers who specialize in Music Scoring, Video Post Sweetening, A.D.R. and Foley.
Associate Members are Sound Specialists, such as Sound Editors, Technicians, Recordists, and Microphone Boom Operators. Corporate Membership is open to companies in the Audio and Video Fields.