1 Scope

This Recommendation | International Standard specifies an ASN.1 type (see ITU-T Rec. X.680 | ISO/IEC 8824-1) whose abstract values represent instances of the W3C XML Information Set. It also specifies binary encodings for those values, using ASN.1 Encoding Control Notation (see ITU-T Rec. X.692 | ISO/IEC 8825-3). NOTE - These encodings are called fast infoset documents.

This Recommendation | International Standard also specifies techniques that:
- minimize the size of fast infoset documents;
- maximize the speed of creating and processing fast infoset documents;
- allow the specification (by the generator of a fast infoset document) of additional processing data.

The first two techniques involve the use of conceptual vocabulary tables. The set of vocabulary tables and the nature of their entries is fully defined in this Recommendation | International Standard, but their representation in computer memory is outside the scope of this Recommendation | International Standard. Provision for transfer or storage of, or a formal notation for displaying or specifying, vocabulary tables to be used as an external vocabulary is also outside the scope of this Recommendation | International Standard.

The third technique involves the provision of additional processing data and a URI that identifies the form and semantics of that data. The specification of specific forms of additional processing data and their use is outside the scope of this Recommendation | International Standard.

URIs can be used to identify final vocabularies that can be used as either part or all of some new initial vocabulary, but the assignment of specific URIs to specific final vocabularies is outside the scope of this Recommendation | International Standard.

This Recommendation | International Standard specifies built-in restricted alphabets, the addition to vocabulary tables of further restricted alphabets by enumeration, and the use of these vocabulary tables for efficient encoding of character strings.

This Recommendation | International Standard further specifies built-in encoding algorithms for the optimum encoding of certain character strings, and the addition to vocabulary tables of further encoding algorithms identified by URIs, but the definition of these further encoding algorithms and their associated URIs is outside the scope of this Recommendation | International Standard.

In addition, this Recommendation | International Standard specifies a Multipurpose Internet Mail Extensions (MIME) media type that identifies a fast infoset document.