A teletext control codes encoding suggestion
beckiergb at gmail.com
Tue Jan 4 18:42:29 CST 2022
Shall I quote the very standard for which this list was created?
23.1 Control Codes
There are 65 code points set aside in the Unicode Standard for
compatibility with the C0 and C1 control codes defined in the ISO/IEC 2022
framework. The ranges of these code points are U+0000..U+001F, U+007F, and
U+0080..U+009F, which correspond to the 8- bit controls 0016 to 1F16 (C0
controls), 7F16 (delete), and 8016 to 9F16 (C1 controls), respectively. For
example, the 8-bit legacy control code character tabulation (or tab) is the
byte value 0916; the Unicode Standard encodes the corresponding control
code at U+0009. The Unicode Standard provides for the intact interchange of
these code points, *neither adding to nor subtracting from their semantics*.
The semantics of the control codes are generally *determined by the
application with which they are used*. However, in the absence of specific
application uses, they *may be* interpreted according to the control
function semantics specified in ISO/IEC 6429:1992. In general, *the use of
control codes constitutes a higher-level protocol and is beyond the scope
of the Unicode Standard*. For example, the use of ISO/IEC 6429 control
sequences for controlling bidirectional formatting would be a legitimate
higher-level protocol layered on top of the plain text of the Unicode
Standard. *Higher-level protocols are not specified by the Unicode Standard*;
their existence cannot be assumed without a separate agreement between the
parties interchanging such data. [emphasis mine]
In other words, you can use C0 and C1 controls in any way you
want, especially if it's according to another standard such as ISO 6429 or
ISO 2022, or even, *gasp* ETSI 300, also known as teletext! Sorry Kent,
just like your understanding of our proposal is wrong, so is your
understanding of control characters in Unicode.
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