Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of the data. Selected attributes that cannot be visually verified on plots or on screen are interactively queried and verified on screen. In addition, the attributes are tested against a master set of valid attributes. Experienced users of soils information understand that soil descriptions are not homogenous over the extent of mapped soil bodies.
All polygons are closed and lines intersect where intended.
Data have been edgematched across tiles and lines generally match within a 0.01 meter tolerance. Each map unit differs in some respect from all others in a survey area and is uniquely identified. Each individual area is a delineation. Each map unit consists of one or more components. These minor components may be indicated as special features.