My understanding is that the list vars (list1, list2, list3) follow the
same basic expiration rules as eVars. So if a list var is set to expire
on the visit, then any value assigned to that var during the visit will
persist until the visit expires. If it is set to a specific time period,
like month, day, 5 days, etc, the value assigned to that list variable
will persist for that specific time period, beyond the visit.