Parents will refrain from drinking alcohol or smoking (tobacco, marijuana) when they have custody of the children.
On-line suggestions for wording in a parenting plan:
"[party name] may not consume alcoholic beverages, narcotics, or restricted dangerous drugs (except by prescription) within (specify number): hours prior to or during periods of time with the children and may not permit any third party to do so in the presence of the children."
"The children will not be exposed to secondhand cigarette [or marijuana] smoke while in the home or car of either parent."
www.familyrelationslaw.com/parentingplans.html