In the context of a discussion on XML compression, Olivier Dubuisson (France Telecom R&D) has described an XML-based "ASN.1 Markup Language" now under development. According to the documentation, this new form of ASN.1 value notation "was created in Geneva during the January joint meeting of the SG 7 and SC 6 groups, and the format of this value notation is based on XML. This work allows ASN.1 values to be transferred or displayed in a variety of textual of binary formats (PER BER HTML XML plain text, etc.); users can leverage browsers for XML display and still have efficient binary transfer in BER..." ASN.1 [Abstract Syntax Notation One] is "a formal notation used for describing data transmitted by telecommunications protocols, regardless of language implementation and physical representation of these data." Dubuisson reports that the the ASN.1 Project from ITU-T is actually working jointly with ISO on two initiatives: (1) An XML value notation for ASN.1 types (or 'ASN.1 Markup Language') that allow to write values by way of an XML markup whose tags are derivated from the ASN.1 type names. Such an XML value notation can appear in an ASN.1 module, and can be used to display ASN.1 values with an XML browser. When appended with an XML document header and footer, this value notation turns into what could be called 'XML Encoding Rules for ASN.1'. This will be a standard named 'ITU-T Recommendation X.693 - ISO/IEC 8825-4'. (2) An XML Schema to ASN.1 mapping that keeps all the information contained in an XML Schema and translates it into equivalent ASN.1 types and subtype constraints. You can then use ASN.1 standardized encoding rules such as DER (that allow digital signatures and encryption, for example) or PER (to very efficiently transmit data over a radio channel, for example), as well as associated ASN.1 tools, for data that are defined in XML. This will be a standard named ITU-T Recommendation X.694 | ISO/IEC 8825-5."

"One of the main objectives of this XML-related work is to allow ASN.1 specifications (modules) to be used as the schema (in place of XML Schema, RELAX...) against which the XML data have to be checked. Protocols can take advantage of both the compact standardized ASN.1 encodings (such as the Packed Encoding Rules), and browser capabilities to display XML data (possibly using style sheets)."

Some "potential application domains for the ASN.1 Markup Language: [1] WML (Wireless Markup Language, for WAP phones) In this case, for example, the PER encoding rules of ASN.1 would give a much more efficient (compressed) encoding than the ad-hoc Binary XML; [2] HDML (Handheld Device Markup Language) for mobile phones and PDAs; [3] SyncML (Synchronisation Markup Language); [4] VoiceXML; [5] tML (telecommunications Markup Language); [6] IPDR (Internet Protocol Detail Record)."