This is my issue with Round-tripping SPARQL Update and RDF (either Turtle or RDF/XML)


http://www.ietf.org/rfc/rfc3987.txt

Below is cut from ^^

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Duerst & Suignard           Standards Track                    [Page 12]

RFC 3987         Internationalized Resource Identifiers     January 2005


      conversion using [RFC3490] may be able to better deal with
      backwards compatibility issues in case mapping and resolution are
      separated, as in the case of using an HTTP proxy.

   Note: Internationalized Domain Names may be contained in parts of an
      IRI other than the ireg-name part.  It is the responsibility of
      scheme-specific implementations (if the Internationalized Domain
      Name is part of the scheme syntax) or of server-side
      implementations (if the Internationalized Domain Name is part of
      'iquery') to apply the necessary conversions at the appropriate
      point.  Example: Trying to validate the Web page at
      http://r&#xE9;sum&#xE9;.example.org would lead to an IRI of
      http://validator.w3.org/check?uri=http%3A%2F%2Fr&#xE9;sum&#xE9;.
      example.org, which would convert to a URI of
      http://validator.w3.org/check?uri=http%3A%2F%2Fr%C3%A9sum%C3%A9.
      example.org.  The server side implementation would be responsible
      for making the necessary conversions to be able to retrieve the
      Web page.

   Systems accepting IRIs MAY also deal with the printable characters in
   US-ASCII that are not allowed in URIs, namely "<", ">", '"', space,
   "{", "}", "|", "\", "^", and "`", in step 2 above.  If these
   characters are found but are not converted, then the conversion
   SHOULD fail.  Please note that the number sign ("#"), the percent
   sign ("%"), and the square bracket characters ("[", "]") are not part
   of the above list and MUST NOT be converted.  Protocols and formats
   that have used earlier definitions of IRIs including these characters
   MAY require percent-encoding of these characters as a preprocessing
   step to extract the actual IRI from a given field.  This
   preprocessing MAY also be used by applications allowing the user to
   enter an IRI.

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