The Geography Markup Language (GML) is an XML encoding in compliance with ISO 19118 for the transport and storage of geographic information modelled in accordance with the conceptual modelling framework used in the ISO 19100- series of International Standards and including both the spatial and non-spatial properties of geographic features.This part of ISO 19136 defines the XML Schema syntax, mechanisms and conventions that:— provide an open, vendor-neutral framework for the description of geospatial application schemas for the transport and storage of geographic information in XML;— allow profiles that support proper subsets of GML framework descriptive capabilities;— support the description of geospatial application schemas for specialized domains and information communities;— enable the creation and maintenance of linked geographic application schemas and datasets;— support the storage and transport of application schemas and datasets;— increase the ability of organizations to share geographic application schemas and the information they describe.