The concept central to the structure of the sections library is that the section property data associated with a group of sections should reflect the data tables published by manufacturers or industry organisations. With this in mind the data displayed in the Sections Table in the Library Window should reflect the published section properties. Each column of data in this table represents a field. In order to utilise this data in Multiframe it is necessary to identify which section property that a field represents. For some types of sections, typically symmetric section, several section properties may be mapped to the same field. In addition, a factor must be specified with each field to convert the value in the field to the base units of newtons, metres and kilograms.