Most meeting directories for AA have a "Key" as to what the abbreviations mean.
Usually, after the O=Open meeting, they put in the disclaimer, visitors welcome, only alcoholics share, or words to that effect.
C = Closed meeting, alcoholics only
NS = Non Smoking
WC = Wheel Chair Accessible
etc
I have seen this all over the country and even in on line meeting listings for various areas of the country.
J M H O
Love and hugs,