Redirection samples:
- urn:ietf:rfc:2141 => http://www.ietf.org/rfc/rfc2141.txt
- urn:ietf:std:3 => http://www.ietf.org/rfc/rfc1123.txt
- urn:ietf:fyi:3 => http://www.ietf.org/rfc/rfc1175.txt
- urn:ietf:bcp:10 => http://www.ietf.org/rfc/rfc5680.txt
- urn:ietf:id:ietf-avt-dtls-srtp-07 => http://www.ietf.org/id/draft-ietf-avt-dtls-srtp-07.txt
- urn:issn:0028-0836 => http://urn.issn.org/urn:issn:0028-0836
- urn:issn:00280836 => http://urn.issn.org/urn:issn:00280836
- urn:isbn:4-8399-0454-5 => http://www.amazon.co.jp/exec/obidos/ASIN/4839904545