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World Wide Vision Initiative

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WWVi's comments on ARIB BML

World Wide Vision Initiative (WWVi) has studied ARIB STD B-24 "Data Coding and Transmission Specification for Digital Broadcasting", which was developed and published by the Association of Radio Industries and Businesses (ARIB). After studying the specification, which is also known as "BML", we concluded that it has a number of defects as a public specification. Below are the points that we believe need to be refined:
  1. Interoperability with the Internet is not taken into account. Consequently, the BML browser will not be able to display content in HTML.
  2. If interoperability should be pursued in the future, the current version of BML, by nature, has difficulties as described below:
    • The character repertoire which is defined to be encoded in an EUC-JP based character encoding scheme is not clearly defined, and there is no conversion table to and from Unicode. In addition, because JIS X 0201, which substitutes "overline" for "tilda" (~), is assigned for the characters under character point 128, URI will not be resolved properly.
    • "Gaiji" which are assigned to the Private Use Area of Unicode can never be  interoperable. It is more appropriate to approach these "gaiji" by a markup based strategy.
    • Integration with other markup language modules will not be possible because BML does not use a namespace.
  3. The specification includes ambiguous, and sometimes misleading, description. It does not even make sense in some definitions:
    • No substantial definition for B-XML is given. Judging from circumstantial information, we reached an understanding that "B-XML is an XML document that can be converted to BML by an XSL stylesheet, which only uses a subset of the XSLT commands". No constraint is placed on the source document.
    • Although BML 'quotes' a considerable amount of W3C technology, such as XML, it does not conform to W3C technology. On the contrary, as a similar, but not identical, specification, it prevents interoperability.
    • The specification does not contain sufficient description for understanding BML, which makes it difficult for possible new entrants to enter the market.
It may be true that most of the reasons for the problems decribed above is that XML and relevant technology were not yet made available at the time of development. However, if interoperability with the Internet should ever be considered in the future, these problems need to be removed at an early stage.

[ This text is translated from the original document in Japanese. ]

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