Proposed Canon
Provisions are food that has been prepared by Erfworlders for later consumption (while on campaign, a long cross-country trek, or other times the Unit is away from a City for an extended period). While Rations may be kept for long term consumption as provisions, provisions may also be created through cooking of meat taken from hunted wildlife, crops grown on farms, or edibles foraged in the wilderness (or in the case of some uncouth individuals, inside city limits).
Through the use of provisions, it is not necessary to pay full upkeep for Units.
Cities produce provisions as part of their normal operation, usually from local farms.