1462 Industry Foundation Classes XML Text (Mark-up) The Industry Foundation Classes (IFC) data model is intended to describe building and construction industry data. ifcxml is an XML-based format that is suitable for interoperability with XML tools and exchanging partial building models. 1 Digital Preservation Department / The National Archives 23 Sep 2014 http://www.buildingsmart-tech.org/downloads/accompanying-documents/guidelines/ifcXML%20Implementation%20Guide%20v2-0.pdf 23 Sep 2014 fmt/663 PUID ifcXML File extension 995 Industry Foundation Classes XML XML declaration tag shortly followed by declaration of iso_10303_28 namespace 1 Absolute from BOF 0 0 3C3F786D6C2076657273696F6E3D(22|27)312E30(22|27){0-32}69736F5F31303330335F3238 Has priority over 638 Extensible Markup Language