Introduction Rules for Authoring KML Application Profiles

OGC 07-147r2 2 Copyright © 2007, 2008 Open Geospatial Consortium, Inc. All Rights Reserved. 2 Conformance

2.1 Conformance requirements

A KML resource that conforms to this standard shall: a satisfy all requirements stipulated in this document; b be well-formed as defined in the W3C XML 1.0 standard; c pass all relevant test cases specified by the Abstract Test Suite ATS provided in OGC document 07-134r2.

2.2 Application Profiles

2.2.1 Introduction

An application profile defines a set of elements derived from one or more base standards for the purpose of: • promoting interoperability; and • meeting the requirements of a particular application domain.

2.2.2 Rules for Authoring KML Application Profiles

A KML profile can restrict or extend KML to the extent permitted by this standard. The KML schema provides a number of extension points that may be exploited in a profile. While a profile shall not contradict the standard, it may restrict the choice of options or introduce new elements or do both. Documents that conform to the KML standard may contain elements and attributes that are not part of the standard but are defined in an application profile. Such elements and attributes—called foreign information items—must not reside within the KML namespace; they shall be placed in another namespace. Application profiles shall not redefine any KML components structurally or semantically within the KML namespace. Application profiles which extend KML shall: • define the XML structure of any new elements and attributes in a valid application profile schema that imports the KML schema; OGC 07-147r2 Copyright © 2007, 2008 Open Geospatial Consortium, Inc. All Rights Reserved. 3 • add new elements to existing concrete KML elements by substitution only, where permitted by the KML schema; • derive any new complex types of complex content directly or indirectly by extension from kml:AbstractObjectType; • derive any new complex types of complex content by extension from the relevant KML abstract type whose semantics it shares. EXAMPLE: a new feature type shall derive from kml:AbstractFeatureType. • declare any new elements and attributes as optional, i.e. minOccurs=0, to support the KML update mechanism. This however does not preclude asserting minimum occurrence constraints as conformance rules within supplementary normative application profile documentation. Application profiles that extend KML should: • place any extension elements and attributes in a vendor-neutral namespace to support any future potential integration with the KML standard, and encourage interoperability in general. An adopted OGC application profile that extends KML should: • be based on a source mass market application profile that is supported by running code; • preferably maintain or else deprecate the namespace of a source application profile from which it derives, ifwhere the source profile is in popular use within the mass market. This is to ensure backwards compatibility with existing instances and consumers of the source profile; • provide a structural and semantic mapping between any profile components which have changed from their original source profile. Authors of application profiles are encouraged to submit their extensions to OGC for standardization. This does not preclude any resulting OGC application profile from being merged later into the KML standard. 3 Normative references The following normative documents contain provisions that, through reference in this text, constitute provisions of this part of OGC 07-147r2. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply; however, parties to agreements based on this part of OGC 07-147r2 are encouraged to investigate the possibility OGC 07-147r2 4 Copyright © 2007, 2008 Open Geospatial Consortium, Inc. All Rights Reserved. of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. OGC 07-134r2, OGC KML 2.2 - Abstract Test Suite IETF RFC 4287, Atom Syndication Format. Available from: http:tools.ietf.orghtmlrfc4287 OASIS Extensible Address Language XAL 2.0. Available from: http:www.oasis- open.orgcommitteesciqdownload.html IETF RFC 3966, The tel URI for Telephone Numbers. Available from: http:tools.ietf.orghtmlrfc3966 ISO 8601:2004, Data elements and interchange formats — Information interchange — Representation of dates and times IETF RFC 3986, Uniform Resource Identifier URI: Generic Syntax. Available from: http:tools.ietf.orghtmlrfc3986 W3C HTML 4.01 Specification. Available from: http:www.w3.orgTRhtml4 W3C XHTML 1.0, The Extensible HyperText Markup Language. Available from: http:www.w3.orgTRxhtml1 W3C Extensible Markup Language XML 1.0. Available from: http:www.w3.orgTRREC- xml W3C Namespaces in XML 1.0. Available from: http:www.w3.orgTRREC-xml-names W3C XML Schema Part 1: Structures. Available from: http:www.w3.orgTRxmlschema-1 W3C XML Schema Part 2: Datatypes. Available from: http:www.w3.orgTRxmlschema-2 4 Terms and symbols

4.1 Terms and definitions