Specifies the code that represents the basis of the dimensional data defined in the piping specialty part data. Set this value to recognize those components that require special treatment in terms of interpreting the symbol dimensional data. For example, the valve symbol is designed on the basis of a face-to-face dimension. However, the manufacturer provides the face-to-center dimension. The symbol can be designed to react accordingly on the basis of the value of this property. Valid codes are listed in the AllCodeLists.xls workbook on the PartDataBasis sheet in the Codelist Number column.