Bill Wilson or Bill W was the co-founder of Alcoholics Anonymous (AA), a fellowship of self-help groups dedicated to helping alcoholics recover from their addiction. According to the AA tradition of anonymity,Wilson was and still is commonly known as "Bill W."
Many people that have been in AA use the term “Bill W.� to ask or identify themselves as alcoholic’s without disclosing to the general public.
You will see meetings posted in the daily events calendars on ships announcing meeting of Friends of Bill W.