OSGeometryTopology.xsd. Change of osgb namespace and removal of AbstractLineStringPropertyType. v2.5 2010/11/25 Ordnance Survey, (c) Crown Copyright. All Rights Reserved Nov 2010. See http://www.ordnancesurvey.co.uk for guidelines and related information This schema defines the geometry and topology extensions to GML 2.1.2. '+' Natural direction, '-' reverse direction