The URL within a multi-line <link> tag or the URL to access for a web service.
When used within <web_service>, the return data is placed in a variable named web_service_value.
Child of: <link>, <web_service>
Parent of: Nothing
Examples:
<link>
<url>http://www.my_site.com</url>
<height>436</height>
<width>626</width>
</link>
<web_service>
<url>http://www.my_site.com/my_web_service.asp</url>
<next_node>a_node</next_node>
</web_service>