forms of XRI synonyms can be resolved using the same http- or https-based resolution protocol. The results of XRI resolution are an XML document called an XRDS (Extensible Resource Descriptor Sequence). XRDS documents are the basis for the Yadis identity service discovery protocol that is now part of OpenID. XRIs are also backwards compatible with the DNS and IP addressing systems, so it is possible for domain names and IP addresses to be used as i-names (or, in rare cases, as i-numbers). Like DNS names, XRIs can also be delegated, i.e., nested multiple levels deep, just like the directory names on a local computer file system. For example, a company can register a top-level (global) i-name and i-number for itself, and then assign second- or lower-level (community) i-names and i-numbers to its divisions, employees, etc. Examples The following examples conform to the i-number specifications published in the XDI.org Global Services Specifications. Note that they do not include the xri://'' prefix as this is optional with absolute XRIs. Global I-Numbers =!1000.a1b2.93d2.8c73 (Personal) @!1000.9554.fabd.129c (Organizational) !!1000 (Network — reserved for XDI.org-accredited i-brokers) Community i-numbers (second-level) =!1000.a1b2.93d2.8c73!3ae2 (Personal) @!1000.9554.fabd.129c!2847.df3c (Organizational) !!1000!de21.4536.2cb2.8074 (Network) Community i-numbers (third-level) =!1000.a1b2.93d2.8c73!3ae2!1490 (Personal) @!1000.9554.fabd.129c!2847.df3c!cfae (Organizational) !!1000!de21.4536.2cb2.8074!9fcd''' (Network) See also Global context registries I-name XRI (Extensible Resource Identifier) XDI (XRI Data Interchange) Social Web Zooko's triangle External links OASIS XRI Technical Committee OASIS XDI Technical Committee XDI.org XDI.org Global Services Specifications. The Social Web: Creating An Open Social Network with XDI in the Planetwork Journal. Identifiers