[W/K] :: Uniform Resource Locator

  uniform resource locator
       n : the address of a web page on the world wide web [syn: URL,
            universal resource locator]

  Uniform Resource Locator
       
           (URL, previously "Universal") A standard
          way of specifying the location of an object, typically a web
          page, on the Internet.  Other types of object are described
          below.  URLs are the form of address used on the World-Wide
          Web.  They are used in HTML documents to specify the target
          of a hyperlink which is often another HTML document
          (possibly stored on another computer).
       
          Here are some example URLs:
       
           http://www.w3.org/default.html
           http://www.acme.co.uk:8080/images/map.gif
           http://www.foldoc.org/?Uniform+Resource+Locator
           http://www.w3.org/default.html#Introduction
           ftp://wuarchive.wustl.edu/mirrors/msdos/graphics/gifkit.zip
           ftp://spy:secret@ftp.acme.com/pub/topsecret/weapon.tgz
           mailto:fred@doc.ic.ac.uk
           news:alt.hypertext
           telnet://dra.com
       
          The part before the first colon specifies the access scheme or
          protocol.  Commonly implemented schemes include: ftp,
          http (World-Wide Web), gopher or WAIS.  The "file"
          scheme should only be used to refer to a file on the same
          host.  Other less commonly used schemes include news,
          telnet or mailto ({e-mail).
       
          The part after the colon is interpreted according to the
          access scheme.  In general, two slashes after the colon
          introduce a hostname (host:port is also valid, or for FTP
          user:passwd@host or user@host).  The port number is usually
          omitted and defaults to the standard port for the scheme,
          e.g. port 80 for HTTP.
       
          For an HTTP or FTP URL the next part is a pathname which is
          usually related to the pathname of a file on the server.  The
          file can contain any type of data but only certain types are
          interpreted directly by most browsers.  These include HTML
          and images in gif or jpeg format.  The file's type is
          given by a MIME type in the HTTP headers returned by the
          server, e.g. "text/html", "image/gif", and is usually also
          indicated by its filename extension.  A file whose type is
          not recognised directly by the browser may be passed to an
          external "viewer" application, e.g. a sound player.
       
          The last (optional) part of the URL may be a query string
          preceded by "?" or a "fragment identifier" preceded by "#".
          The later indicates a particular position within the specified
          document.
       
          Only alphanumerics, reserved characters (:/?#"<>%+) used for
          their reserved purposes and "$", "-", "_", ".", "&", "+" are
          safe and may be transmitted unencoded.  Other characters are
          encoded as a "%" followed by two hexadecimal digits.  Space
          may also be encoded as "+".  Standard SGML "&;"
          character entity encodings (e.g. "é") are also accepted
          when URLs are embedded in HTML.  The terminating semicolon may
          be omitted if & is followed by a non-letter character.
       
          The authoritative W3C URL specification
          (http://www.w3.org/hypertext/WWW/Addressing/Addressing.html).
       
          (2000-02-17)