One or more contexts that are recognized as a spatially discrete unit. Most features are comprised of the contexts that reside in a single depositional basin and the basin itself; for example, the layers in a single pit or cellar and the cellar walls. Other examples include a posthole’s fill and its mold, or the bricks comprising a foundation wall, the builder’s trench in which the bricks are set, and the fill of the trench. Features are numbered uniquely within sites and carry a F-prefix.