Generally, if a Meeting is NOT listed as 'Open, it should be assumed to be a Closed Meeting.
Open Meetings: Anybody may attend.
Closed Meetings: Only Alcoholics or People who think they may have a drink problem may attend.
'Chit' System: Meeting Attendance Chits.
Non Restrictive: Alcoholics & Problem Drinkers may attend any AA Meeting, N.R (non restrictive) is added to Meeting details, where the name of the Meeting may suggest exclusiveness, i.e 'Oldtimers Lunchtime'