Internet Draft Network Working Group C. Portele Request for Comment Interactive Instruments Category: Informational C. Reed Expires: November 1, 2011 Open Geospatial Consortium May 2, 2011 GML Media Type draft-portele-ogc-gml-mime-00 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on November 1, 2011. Copyright Notice Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract This document standardizes a new media type -- application/gml+xml -- for use in exchanging geographical models represented in a compliant Geography Markup Language. 1. Introduction GML (Geography Markup Language) is an international standard adopted by both the Open Geospatial Consortium (OGC) and the International Organization for Standardization (ISO). GML is Portele and Reed [Page 1] An XML grammar for modeling geographic information. The GML format is an actual media format. 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. 2. Notational Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. The terms "element" and "document element" in this document are to be interpreted as in [XML]. The term "XML namespace" is to be interpreted as in [NAMESPACES]. 3. Media Registration for GML MIME media type name: Application MIME subtype name: Standards Tree -gml+xml Required parameters: None Optional parameters: The charset parameter of application/gml+xml is handled in the same fashion as for application/xml, as specified in Section 3.2 of [RFC3023 Encoding considerations: As per Section 3.2 of [RFC3023]. Published specification: The latest version at the time of this writing is 3.2.1 which is published by ISO as ISO 19136:2007. The standard can be accessed online at http://www.opengeospatial.org/standards/gml. The OGC GML MIME specification has also been approved by the OGC Membership and is published here: http://portal.opengeospatial.org/files/?artifact_id=37743 Additional information: 1. Magic number(s): None. 2. File extension(s): .xml or .gml 3. Macintosh file type code: TEXT 4. Object Identifiers: None Intended usage: Common Portele and Reed [Page 2] Author/Change controlled: 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 standard. MIME 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 and in the OGC Policies and Procedures here: 4. Interoperability and usage 4.1 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. 4.2 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. The use of 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 browzer applications, and so forth. 5.0 Security considerations: The OGC Geography Markup Language (GML) is a generic format for exchanging geographic information, but application designers must not assume that it provides generic protection against security threats. RFC 3023, section 10, discusses security concerns for generic XML, which are 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. 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. Portele and Reed [Page 3] 6. IANA Considerarations This document specifies a new media type. If approved, IANA will add this media type to their media types registry as specified in [RFC4288]. 7. References 7.1. Normative References [OGC GML] Portele, Cox, Whiteside, Daisy, 20 April 2006, [NAMESPACES] Bray, T., et. al., "Namespaces in XML 1.1", 4 February 2004, [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3023] Murata, M., St. Laurent, S., and D. Kohn, "XML Media Types", RFC 3023, January 2001. [XML] Bray, T., et. al., "Extensible Markup Language (XML) 1.0 (Fourth Edition)", 29 September 2006, 7.2 Informative References [OGC URN] A Uniform Resource Name (URN) namespace for the Open Geospatial Consortium (OGC) draft-creed-ogc-urn-03.txt Authors Address: Carl Reed, PhD Open Geospatial Cosortium 35 Main Street Wayland, MA Email: creed@opengeospatial.org Clemens Portele Interactive Instruments Bonn, Germany portele@interactive-instruments.de