XDF_017.xsd - eXtensible Data Format - version 0.17 Date: March 27, 2002 XML Schema. An XDF document contains arrays and data structures. It is designed to be both an interchange format for scientific data and to be of archival quality. Multidimensional tables and scalar or vector fields are represented in a consistent way and become thoroughly self describing. Axial information is well described so that the space in which each part of the data structure resides is fully described. This means that XDF provides a consistent way to hold spectra with their wavelength scales, images with coordinate axes, vector fields with unitDirection, data cubes in complicated spaces, tables with column headers, and series of tables with each table having a unique name.