Re: OCR characters

From: Otto Stolz (Otto.Stolz@uni-konstanz.de)
Date: Fri Aug 16 2002 - 10:29:45 EDT


Eric Muller had written:

> In our OCR fonts, we have two glyphs named "erase" [...]

> and "grouperase" [...] I suspect those are mandated by these
> standards. On the other hand, and I can't find traces of those in
> Unicode,

Arnold F. Winkler wrote:
> I believe, Eric is talking about the characters on the attached page 8 of
> the OCR standard.

I don't have ISO 1073 at hand, only the German
- DIN 66 008 (Jan 1978), which is essentially identical with ISO
1073/I-1976,
   and
- DIN 66 009 (Sept. 1977), which is based on, but not identical with,
   ISO 1073/II-1976.

DIN 66 008 contains the figure reported by Arnold Winkler. This standard
does not specify the intended usage of these characters -- not beyond their
expressive names.

DIN 66 009 says about the equivalent OCR-B characters (my translation):
> In case of a typo, a keyboard-driven device will print the Character
Erase
> on top of an erroneous character. This will cause the OCR reading device
> to ignore this position.
> The Group Erase may be either drawn by hand, or printed as discussed in
> the previous paragraph. It will cause the OCR reading device to ignore
> this position.

So, these characters would never be read by an OCR device. They would be
printed only in response to a function key (such as Erase Backwards), but
never sent (encoded as characters) to a device. This means, that they will
not normally be encoded, hence there will probably no need to assgin Uni-
codes to them.

The only exception could be a text discussing these characters, and
their usage. I think, this sort of text would use figures rather than
characters, to show the effect of overprinting in several variants.
(The Erase, and the erased, character's positions may slightly differ.)

So I guess, these characters are deliberately left off Unicode.

Best wishes,
   Otto Stolz



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