--------------------------------- Cass--
May I answer for Shar? (I don't mean to butt in, but am afraid she might be reluctant to reply.) Bill W. cofounded Alcoholics Anonymous. Members have traditions of not using their last names and not revealing their membership in the organization to others (lest it become an unintended source of pride that sabotages sobriety, I think). Because I am not a member, I am free to tell you that "Friends of Bill W." is a kind of shorthand some use to refer to AA without naming it.
I believe that the same traditions are a part of most, if not all, Anonymous programs that have grown out of AA's remarkably successful 12-step program. I don't know what shorthand references they use, if any.
Best wishes--medlib