From: "Jim Allan" <[EMAIL PROTECTED]>The common 3of9 bar code are normally implemented in a font in which the bar code characters are placed in the position of the corresponding ASCII or EBCDIC characters. This is a simple cipher fonts and the bar code characters are unique representations of uppercase Latin letters and digits. They are simply bar code versions of the abstract characters. Each character has a semantic: A, B, C and so forth.
But if, in your opinion Theban and 3of9 bar code is on the cipher side
of a line and Ewellic is on the other side I would like to know the
logic on which this line is drawn.
With that definition,
BarCodes are not a script, as they're a technical convention (similar to the
Unicode assignment of arbitrary numeric codepoints to characters) which in
itself has no semantic, but is used to represent a script (or another) in
order to be read by automated devices that will decode it to render it back
as a character or something else. Also Barcodes have strict technical glyph
constraints which do not qualify them as abstract characters.
In short, 3of9 bar code is normally treated as a font style and the text is rendered by changing to an appropriate font.
The text for the bar code is coded as pure ASCII or EBCDIC plain text and probably now sometimes as Unicode text.
There are no constraints on plain text to be output in 3of9 bar code format other than that the characters must be limited to those representable by the bar code and each bar code line or portion of text to be displayed as 3of9 bar code must begin and end with the character conventionally assigned to asterisk. This character may not be used internally in the line.
Some other kinds of bar codes are more complex, involving built-in checksums or different cipher characters in the first half and and second half of the bar code. But all that I have worked with are principally ciphers of a kind with certain formatting constraints.
Jim Allan
