capabilities XML spatial reference system

OpenGIS © Specification OGC 04-094 Copyright © Open Geospatial Consortium, Inc 2005 7

4.10 opaque

not visible, accessible or meaningful to a client application

4.11 XLink link

an explicit relationship between resources or portions of resources [14]

4.12 XLink linking element

an XLink-conforming XML element that asserts the existence of an XLink link [14]

4.13 locator attribute href

the attribute that supplies the data a URI reference that allows an XLink application to find a remote resource or resource fragment [14]

4.14 traversal

using or following an XLink link for any purpose [14] 5 Conventions

5.1 Normative verbs

In the sections labeled as normative, 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 Internet RFC 2119 [1].

5.2 Abbreviated terms

CGI Common Gateway Interface DCP Distributed Computing Platform DTD Document Type Definition EPSG European Petroleum Survey Group GIS Geographic Information System GML Geography Markup Language HTTP Hypertext Transfer Protocol HTTPS Secure Hypertext Transfer Protocol SSL Secure Socket Layer IETF Internet Engineering Task Force MIME Multipurpose Internet Mail Extensions OGC Open GIS Consortium OWS OGC Web Service URL Uniform Resource Locator OpenGIS © Specification OGC 04-094 Copyright © Open Geospatial Consortium, Inc 2005 8 WFS Web Feature Service XML Extensible Markup Language

5.3 Use of examples

This specification makes extensive use of XML examples. They are meant to illustrate the various aspects of a web feature service discussed in this specification. While every effort has been made to ensure that the examples are well formed and valid, this goal was sacrificed for the sake of clarity in many cases. For example, many examples are formatted in a specific way to highlight a particular aspect that would render the example invalid from the perspective of an XML validation tool. Further, most examples reference fictitious servers and data. Thus, this specification does not assert that any XML or keyword-value pair encoded example, copied from this document, will necessarily execute correctly or validate using a particular XML validation tool. Only sections marked as normative should be expected to be well-formed and valid XML or XML Schema documents. 6 Basic service elements

6.1 Introduction

This section describes aspects of OGC Web Feature Service behavior that are independent of particular operations or are common to several operations or interfaces. 6.2 Version numbering and negotiation 6.2.1 Version number form The published specification version number contains three positive integers, separated by decimal points, in the form x.y.z. The numbers y and z will never exceed 99. Each OWS specification is numbered independently.

6.2.2 Version changes

A particular specifications version number shall be changed with each revision. The number shall increase monotonically and shall comprise no more than three integers separated by decimal points, with the first integer being the most significant. There may be gaps in the numerical sequence. Some numbers may denote experimental or interim versions. Service instances and their clients need not support all defined versions, but must obey the negotiation rules below.