A WMS_Capabilities document is returned in response to a GetCapabilities request made on a WMS. The Name is typically for machine-to-machine communication. The Title is for informative display to a human. The abstract is a longer narrative description of an object. List of keywords or keyword phrases to help catalog searching. A single keyword or phrase. An OnlineResource is typically an HTTP URL. The URL is placed in the xlink:href attribute, and the value "simple" is placed in the xlink:type attribute. A container for listing an available format's MIME type. General service metadata. Information about a contact person for the service. A Capability lists available request types, how exceptions may be reported, and whether any extended capabilities are defined. It also includes an optional list of map layers available from this server. Available WMS Operations are listed in a Request element. For each operation offered by the server, list the available output formats and the online resource. Available Distributed Computing Platforms (DCPs) are listed here. At present, only HTTP is defined. Available HTTP request methods. At least "Get" shall be supported. The URL prefix for the HTTP "Get" request method. The URL prefix for the HTTP "Post" request method. An Exception element indicates which error-reporting formats are supported. Individual service providers may use this element to report extended capabilities. Nested list of zero or more map Layers offered by this server. Identifier for a single Coordinate Reference System (CRS). The EX_GeographicBoundingBox attributes indicate the limits of the enclosing rectangle in longitude and latitude decimal degrees. The BoundingBox attributes indicate the limits of the bounding box in units of the specified coordinate reference system. The Dimension element declares the existence of a dimension and indicates what values along a dimension are valid. Attribution indicates the provider of a Layer or collection of Layers. The provider's URL, descriptive title string, and/or logo image URL may be supplied. Client applications may choose to display one or more of these items. A format element indicates the MIME type of the logo image located at LogoURL. The logo image's width and height assist client applications in laying out space to display the logo. A Map Server may use zero or more MetadataURL elements to offer detailed, standardized metadata about the data underneath a particular layer. The type attribute indicates the standard to which the metadata complies. The format element indicates how the metadata is structured. A Map Server may use zero or more Identifier elements to list ID numbers or labels defined by a particular Authority. For example, the Global Change Master Directory (gcmd.gsfc.nasa.gov) defines a DIF_ID label for every dataset. The authority name and explanatory URL are defined in a separate AuthorityURL element, which may be defined once and inherited by subsidiary layers. Identifiers themselves are not inherited. A Map Server may use DataURL offer a link to the underlying data represented by a particular layer. A Map Server may use FeatureListURL to point to a list of the features represented in a Layer. A Style element lists the name by which a style is requested and a human-readable title for pick lists, optionally (and ideally) provides a human-readable description, and optionally gives a style URL. A Map Server may use zero or more LegendURL elements to provide an image(s) of a legend relevant to each Style of a Layer. The Format element indicates the MIME type of the legend. Width and height attributes may be provided to assist client applications in laying out space to display the legend. StyleSheeetURL provides symbology information for each Style of a Layer. A Map Server may use StyleURL to offer more information about the data or symbology underlying a particular Style. While the semantics are not well-defined, as long as the results of an HTTP GET request against the StyleURL are properly MIME-typed, Viewer Clients and Cascading Map Servers can make use of this. A possible use could be to allow a Map Server to provide legend information. Minimum scale denominator for which it is appropriate to display this layer. Maximum scale denominator for which it is appropriate to display this layer.