Schema IFC4.2 This sub-category was created to discuss the draft of IFC4.2, which includes the new IfcBridge extensions. Please post a separate topic for each item or issue you wish to respond to. Serializations A category for the discussion of IFC schema serializations (e.g. STP, XML, JSON, TTL, RDF, etc.). Schemas Schema IFC4.3 This sub-category is reserved for discussions concerning the implementation of the IFC4.3 Candidate Standard, including Rail, Road, Ports & Waterways, and other implementation projects.