W3C home > Mailing lists > Public > wai-xtech@w3.org > September 2003

Re: classification of Braille [signs] in Unicode

From: Lloyd G. Rasmussen <lras@loc.gov>
Date: Tue, 23 Sep 2003 15:30:42 -0400
Message-Id: <3.0.5.32.20030923153042.00868100@sun8.LOC.GOV>
To: wai-xtech@w3.org
Cc: jdix@loc.gov

Your analysis looks OK to me.  I don't know of any implementations of the
x2800-28ff range of code points for braille exchange.  It is a good thing
that this range has been defined in Unicode.

In writing the Z39.86 digital talking book standard and discussing braille
inclusions, we were most likely thinking of braille that would be readable
on currently available equipment without further translation, not having
experience with doing braille any other way.  We were probably not thinking
of using this range, although it would solve problems of conflicts with the
angle brackets, ampersand, etc.  Clearly, x2800-28ff could be used in DTB
text content files and perhaps should be, but I don't know of any software
which would know how to process such characters.  

Braille embossers and displays outside of North America are sometimes set
up with part of the mapping from ASCII to braille different from the North
American mapping because of different expectations for punctuations and
numbers.  And the mapping used for 0080 to 00ff will vary depending on
whether the bottom dots are being used to represent capitalization or
visual attributes.  Control characters may be shown on a braille display in
some code translation tables, but there is no standardization of this.

Currently, people doing a braille text chat would be exchanging one-byte
characters which have a meaning to the participants, but not a
tightly-defined schema.  English-speaking people who are using braille
keyboards as well as braille displays are likely to write in Grade 2 (now
called "contracted" braille).  In contracted braille, many of the symbols
represent standardized letter groupings or words.  In North American
contracted braille    there are 189 standardized contractions.  I think
German braille has more contractions and Russian has few, if any.  

Bottom line:  I don't think that anything major would be lost by
considering the braille range to be symbols rather than letters, partly
because there is practically no implementation yet, and because there is no
universally accepted mapping between braille code points and print
alphabets.  Any mappings that exist are based on language of the
participants and the purpose of the communication.

I would be happy to hear differing views, however.
Braille is the solution to the digital divide.
Lloyd Rasmussen, Senior Staff Engineer
National Library Service f/t Blind and Physically Handicapped
Library of Congress    (202) 707-0535   <http://www.loc.gov/nls/>
HOME:  <http://lras.home.sprynet.com>
The opinions expressed here are my own and do not necessarily represent
those of NLS.
Received on Tuesday, 23 September 2003 15:30:29 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 27 April 2012 13:15:38 GMT