So far unofficial answer from LA FISDO is this:
If jumpseater is NOT on duty, nor traveling for duty, and it's been 8hrs and their BAC is under .04% (or your company policy limitations), then he/she can partake in consumption of limited quanties of alcohol.
thanks for that... 90 percent of most 121 carriers, like wn, are more restrictive than fsdo rules. just a tip, if you are on wn, and you filled out the triplicate form, don't drink.
jehtplane.... the acronym ACM, stands for additional crew member, up front or back.