Linking

<a> specifies a hyperlink......OCGPSX.
......transform
......xlink:href="<iri>": the referenced resource
.......target="{ _replace | _self | _parent | _top | _blank | <XML name>}": the target display.
                '_replace' displays in the same rectangular area in the same frame.
                '_self' displays in the same frame.
                '_parent' displays in the immediate frameset parent.
                '_top' displays in the full window or tab.
                '_blank' displays in a new un-named window or tab.
                <XML name> displays in the named frame/pane. If it does not exist, it is created with the name.

<style>embeds a style sheet......C.
......type="<MIME type>": the type. The default is "text/css".
......media="<media descriptors>"
......title="<text>": an advisory title.

<foreignObject> includes a foreign object......OCGPS.
......transform
......x="<coord.>": the x coord. of the upper-left corner
......y="<coord.>": the y coord. of the upper-left corner
......width="<length>": the width
......height="<length>": the height

<switch> processes one of the direct child elements......OCGPS.
It evaluates the 'requiredFeatures', 'requiredExtensions' and 'systemLanguage' attributes on its direct child elements in order, and then processes the first child for which these attributes evaluates to true. All other direct child elements will be bypassed.
......transform
......requiredFeatures="<space-separated Feature Strings>": evaluates to true if all features are supported. It evaluates to false otherwise, thus skipping the element. For a complete list of Feature Strings, refer to: http://www.w3.org/TR/SVG11/feature.html
......requiredExtensions="<space-separated IRIs>": evaluates to true if all extensions are supported. It evaluates to false otherwise, thus skipping the element.
......systemLanguage="<comma-separated language names>": evaluates to true if one of the languages specified is supported. It evaluates to false otherwise, thus skipping the element. Eg.:<text systemLanguage="ch, en"><!-- content goes here --></text>