Peter Constable wrote as follows. >Sigh... > >William, CENELEC is an international standards body. Such bodies either >create their own standards or use other international standards. They do >not use PUA codepoints.
Well, the fact of the matter is that Cenelec is trying to achieve a consensus for the implementation of interactive television within the European Union, including, though not only, issues of access for people with hearing and visual problems. The issue of symbols for Audio Description, Subtitle, Signing has been raised. These could be used in graphics on television channels and also in textual electronic programme guides (known as EPGs) available on interactive television channels, that is, listings of the ordinary television programme schedule for all of the available television channels in the particular reception area. In view of the fact that the interactive television system (DVB-MHP, Digital Video Broadcasting - Multimedia Home Platform http://www.mhp.org ) uses Java and Java uses Unicode it is then a matter of deciding how to be able to signal the symbols in a Unicode text stream. The symbols could then be displayed, either from a font or from a Java program recognising the code point and drawing a graphic. In view of the fact that the process of getting regular Unicode code points for the symbols would take quite a time, and indeed that there is as yet no agreement on which symbols to use, and that the implementation of interactive television needs to proceed, it seems to me that putting forward three specific Private Use Area code points for the symbols at this time is helpful to the process. A gentleman has put some logo designs on the web at the following place. http://info.rnib.org.uk/audiodescription/logo/ Readers might perhaps like to have a look at those logos. Peter continued, about my putting forward the PUA code points. >Such things are *not* useful. They do not achieve consistency, not in the >short term, and most certainly not in the long term. If consistency is >needed, the standardization process is used to established standardized >representations. Well, what is the alternative? The code points are in the Private Use Area, so the suggestion avoids the possibility of a non-conformant use of a regular Unicode code point. For the long term, hopefully regular Unicode code points will be achieved. In the short term, my suggesting of some specific code points does not impede consistency and may possibly help to achieve consistency. >Please, if you want to see things encoded as characters, then learn how to >use the established processes for doing so (but please also learn what are >and are not suitable candidates for character encoding). Well, in due course hopefully the symbols will become encoded in regular Unicode, yet the symbol designs have not yet been agreed. However, publishing Private Use Area code points as an interim solution is an established process. One such publication was recently announced in this mailing list and there seemed to be no objection to that publication of suggested Private Use Area code points. Indeed, the Unicode Standard version 3.0 mentions the publishing of Private Use Area code points. I do not know what is the text for Unicode 4.0, though there was some talk of changing the wording of the section about the Private Use Area in this mailing list some time ago. These symbols seem to be as valid as many of the symbols already in the Miscellaneous Symbols section and as valid as those currently going through the registration process. In view of the excellent .pdf files which have appeared about those symbols which are presently going through the registration process I am rather hoping that these symbols will at some future time appear in such a .pdf file as part of the registration process. >And might I also suggest that you create a Yahoo discussion group or MSN >community for PUA use, and then carry on discussion of ways to use the PUA >there rather than here? Reading the information into the Unicode mail list archive is a process of great value to me, so that is the motivation for posting the information in this mailing list. I was not carrying on a discussion of ways to use the PUA. I was simply making an announcement to the people on the list. There may well be people on this list who are interested in interactive television and who are not members of the Cenelec discussion forum and who might like to know of this suggestion. Also, the symbols might well be used in hardcopy television programme listing magazines, so it would be desirable to have them available in fonts. I recognise that some of my suggestions for use of Private Use Area code points are for items that are most likely to remain as Private Use Area code points. For example, those for my eutocode graphics system which allows graphics commands and text to be mixed in a Unicode plain text file as input for a Java program producing a multimedia display; and those which I have suggested for a chess font with pieces on both white and black squares. Although I am hoping that my eutocode graphics system will become widely used in interactive television systems, I accept that it is a specialist application which may be of great interest to some people and of no interest to many other people. Likewise the code points for a chess font, particularly those for chess variants such as Carrera's Chess. However, the symbols for Audio Description, Subtitle, Signing have very widespread use possibilities and so posting my suggested code point allocations for them here in a short note seemed, and still seems, reasonable to me. William Overington 15 July 2003
