(registered 2017-01-09, last updated 2017-01-09) Media type name: application Media subtype name: gml+xml Required parameters: None Optional parameters: "charset": See Section 3 of RFC 7303. "version": If provided, this parameter indicates the major and the first minor version number of the GML version used in the GML document, e.g. "3.2". Syntax: version = 1*DIGIT "." 1*DIGIT The first group of digits is the major version number, the second group is the minor version number. In cases where elements from multiple GML versions are used, the parameter should indicate the highest GML version used in the document. The parameter can be used to provide protocol-specific operations, such as version-based content negotiation in HTTP or in the OGC Web Feature Service. The parameter is a hint, if used in HTTP content negotiation. I.e., client implementations should be prepared to receive content in a different version than requested and server implementations should honour the version parameter during content negotiation, if possible. "profile": If provided, this parameter indicates the GML profiles that the GML document conforms to. This is consistent with the semantics of a profile as laid out in RFC 6906. The parameter can also be used to provide protocol-specific operations, such as profile-based content negotiation in HTTP. A profile is identified by a URI. As a GML document may conform to more than one GML profile, the parameter value is a whitespace-separated list of profile URIs. Syntax: profile = URI *( 1*WSP URI ) The element "URI" is defined by Section 3 of RFC 3986. Profile URIs are assigned by the publisher of the GML profile. The URI should be in the "http" URI scheme and, if dereferenced, should return information about the GML profile. For example, version 2.0 of the GML Simple Feature Level 0 profile specified by OGC is identified by the URI "http://www.opengis.net/def/profile/ogc/2.0/gml-sf0". Encoding considerations: Same as application/xml - see section 9.1 of RFC 7303. Security considerations: The OGC Geography Markup Language (GML) is a generic XML grammar for exchanging geographic information, but application designers must not assume that it provides generic protection against security threats. RFC 7303, Section 10, discusses security concerns for generic XML, which are also applicable to GML. Xlink references in GML documents may cause arbitrary URIs to be dereferenced. In this case, the security issues of RFC 3986, section 7, should be considered. GML documents do not contain active or executable content. GML does not provide privacy or integrity services. If sensitive data requires privacy or integrity protection, those must be provided by the transport, for example, Transport Layer Security (TLS) or HTTPS. There will be cases in which stored data need protection, which is out of scope for this document. The general considerations related to location information apply, for example, see RFC 7946, Section 10, Paragraph 3. Interoperability considerations: Different versions of GML specify different XML Schema documents used for the validation of GML documents. Starting with version 3.2, the GML version information is represented in the namespace. As applications may only support a subset of all published GML versions, the use of the version parameter is recommended. An older version of the OGC Web Feature Service standard (version 1.1) has used unregistered and incorrect media types for GML documents in an HTTP query parameter "outputFormat", namely "text/xml; subtype=gml/2.1.2" and "text/xml; subtype=gml/3.1.1". Producers of GML documents should not use these strings for any other purpose than values of the "outputFormat" query parameter. Published specification: GML (Geography Markup Language) is an international standard adopted by both the Open Geospatial Consortium (OGC) and International Organization for Standardization (ISO). The latest version at the time of writing is GML 3.3. In ISO, GML is published as ISO 19136:2007 and ISO 19136-2:2015. All versions of the standard can be accessed freely online at http://www.opengeospatial.org/standards/gml. Applications which use this media: GML is a generic device-, platform-, and vendor-neutral XML grammar and is supported by a range of applications creating, providing access to and processing geographic information. GML is in use internationally with hundreds of deployed applications able to create and ingest GML payloads, including all of the major GIS vendors, many database providers, earth browser applications, and so forth. Fragment identifier considerations: Fragement identifiers reference XML elements in the document. GML uses an attribute gml:id for such identifiers, which has the XML Schema type ID. Restrictions on usage: None Provisional registration? (standards tree only): As the media type is already in use in OGC standards (e.g., http://docs.opengeospatial.org/is/09-025r2/09-025r2.html) and software implementing the standards, a provisional registration would be appreciated. Additional information: 1. Deprecated alias names for this type: None 2. Magic number(s): None 3. File extension(s): *.xml or *.gml 4. Macintosh file type code: TEXT 5. Object Identifiers: None General Comments: The OGC is an international voluntary consensus standards organization focused on defining and maintaining standards that enable interoperability for using geospatial content and services in any application that requires the use of geospatial content or services. The OGC website is www.opengeospatial.org. Person to contact for further information: 1. Name: Clemens Portele 2. Email: portele&interactive-instruments.de Intended usage: COMMON Author/Change controller: The GML standard is a work product of the Open Geospatial Consortium (OGC). The OGC and the GML Standards Working Group have change control over the GML standard. Media types for use in OGC standards and formats are defined by the OGC Members and discussed and approved by the OGC Naming Authority (OGC-NA). The function and role of the OGC-NA is described in RFC 5165 and in the OGC Policies and Procedures: http://docs.opengeospatial.org/pol/05-020r24/05-020r24.html