OASIS announced that the Extensible Resource Identifier (XRI) Technical Committee has submitted two specifications for consideration by the membership as OASIS Standards. Balloting will begin on May 16, 2008 and extend through the end of the month.
"Extensible Resource Identifier (XRI) Syntax V2.0" specifies the normative syntax and transformation rules for a new type of digital identifier called an XRI (Extensible Resource Identifier). XRIs are called "abstract structured identifiers" -- abstract because they are intended to be resolved via a standard discovery process into other concrete identifiers for a resource, and structured because they may contain self-describing "tags". Abstract structured identifiers are designed for use with digital identity and data sharing infrastructure such as OpenID, OAuth, SAML, information cards, Higgins, XDI, etc.
XRI Syntax 2.0 extends IRI/URI syntax by: (1) Allowing the internal components of an XRI to be explicitly tagged as either persistent or reassignable. (2) Enabling XRIs to contain other XRIs (or IRIs or URIs), a syntactic structure called "cross-referencing" that allows sharing of identifiers, such as generic identifiers or "tags", across multiple authorities and namespaces. (3) Supporting new types of identifier authorities including global context symbols and cross-references.
XRIs build on the foundation of interoperable Web identifiers established by URIs (Uniform Resource Identifiers, RFC 3986) and IRIs (Internationalized Resource Identifiers, RFC 3987). Just as the IRI specification created a new identifier by extending the unreserved character set allowed in generic URIs, and defined rules for transforming IRIs into valid URIs, the XRI Syntax 2.0 specification creates a new identifier by extending the syntax of IRIs and defining transformations of XRIs into valid IRIs (which can then be transformed into valid URIs.)
"Extensible Resource Identifier (XRI) Resolution Version 2.0", a companion specification to the XRI Syntax 2.0 specification for abstract structured identifiers, provides a simple standardized method for performing resource discovery on either HTTP(S) URIs or XRIs. XRI Resolution 2.0 defines a simple generic XML discovery document format called XRDS (Extensible Resource Descriptor Sequence), a standard protocol for requesting XRDS documents using HTTP(S) URIs, and standard protocol for resolving XRIs using XRDS documents and HTTP(S) URIs. Both generic and trusted versions of the XRI resolution protocol are defined (the latter using HTTPS (RFC 2818) and/or signed SAML assertions). In addition, an HTTP(S) proxy resolution service is specified both to provide network-based resolution services and for backwards compatibility with existing HTTP(S) infrastructure.
