[1] Associating Resources with Namespaces <http://www.w3.org/2001/tag/doc/nsDocuments/> (名無しさん)
[2] XML Resource Directory Description Language (RDDL) <http://www.rddl.org/> (名無しさん)
[3] Namespaces and RDDL ( 版) <http://www.w3.org/People/cmsmcq/2001/nsrddl.html>
[4] RDF Site Summary (RSS) 1.0 ( 版) <http://web.resource.org/rss/1.0/>
[5] >>4 は text/html
ですが、 RDDL が埋め込まれています。
[6] Unicode Codepoint Collation URI Document () <https://www.w3.org/2005/xpath-functions/collation/codepoint/>