RE: Unicode Public Review Issues update (braille)

From: Kent Karlsson (
Date: Tue Oct 07 2003 - 09:07:22 CST

> >A question about the issues already open: What is the justification
> >proposing to make Braille Lo?

Shortly before this came up as a "Public Review Issue", I suggested that
Braille characters should not be regarded as ignorable symbols when
collating texts. I.e. that they should have "level one" weights in the
default weighting table. The reason being that they are more often
used for letters than for other things. (However, I did not ask to make
them "Lo"...) That would be for the default ordering. Wanting a more
"alphabetically proper" ordering, would still require tailoring for that
particular correspondence between "ordinary" letters and Braille, but
require converting to the "ordinary" letters. Each such tailoring would
give level 1 weights to most of the Braille characters used in that
of usage.

> Among other things it would make it part of identifiers.
> However, there's
> been some suggestion that this is a bad idea. Whether or not
> a braille
> symbol actually stands for a letter or a digit or a
> punctuation mark is
> entirely dependent on a higher level protocol.

I would agree with your reasoning here. I don't think Braille
should be used for identifiers.

> Also, by making them Lo, any parser that tries to collect
> words, would run
> them together with any surrounding regular letters and
> digits. That seems
> odd, but perhaps its not any more odd than mixing Devanagari and Han.

I.e., this is not so odd at all (a quite different case from
> The original model for these was that your text processing is done in
> non-Braille, and on the last leg to a device, you would transcode the
> regular text to a Braille sequence using a domain and
> language specific
> mapping. Having the codes in Unicode allows you to preserve
> 'final form'
> and transmit that as needed w/o having to also transmit the
> text-to-braille
> mapping(s) that were used to generate the Braille version of
> the text.
> (This assumes that the eventual human reader can do 'autodetection'.)

This does not apply to text that have been manually written in or
translated to Braille (for a particular language). As I have understood
it, writers/transcribers often use(d) peculiar writings, e.g.
that would not occur in "normal" text, the "abbreviations" varied from
"scribe" to "scribe". I'm not familiar with the details though.
Braille can be used also for math and music notation.

B.t.w. Braille often uses "state shifts", e.g. for digits. There is a
Braille code, followed by one or more codes for the letters a-j (if the
script is Latin) which then stand for 1, ..., 9, 0 (the list is
terminated with
any non-a-j code; but decoding the Braille for e.g. 12a is ambiguous,

                /kent k

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