The GML specification declares a large number of XML elements and attributes meant to support a wide variety of capabilities. For example, the GML specification can encode dynamic features, spatial and temporal topology, complex geometric property types and coverages. With such a wide scope, interoperability can only be achieved by defining profiles of GML that deal with a restricted subset of GML capabilities. Such profiles limit the number of GML object types that can appear in compliant schemas and consequently are easier to process. The generation and parsing of Geographic Markup Language (GML) [OGC 03-105r1] and XML Schema [W3C XML-1, W3C XML-2] code are required in the implementation of many components that deal with GML encoded content. This profile defines a restricted but useful subset of XML-Schema and GML to lower the “implementation bar” of time and resources required for an organization to commit for developing software that supports GML. It is hoped that by lowering the effort required to manipulate XML encoded feature data, organizations will be encouraged to invest more time and effort to take greater advantage of GML’s rich functionality.
Development of this profile does not reduce the need for distinct communities of users to develop application schemas (data models) for information sharing. However, to the extent that users’ application schemas fit within the scope of GML-SF capabilities, this profile facilitates the ability to use WFS for interoperable feature data exchange with much less software development investment.