—
The conversion tables were built using Python.
The ISO 8859-X encodings are shown
with C1 control
characters in positions 0x80–0x9f (the C0
controls being the familiar ASCII 0x00–0x1f
plus ␡).
The C1 control codes are from an ancient era of computer history, and
don't seem to have had much
use. Wikipedia
says they were almost never used. Some of the functions they describe
could be implemented in 7-bit environments by using
␛ followed by an ASCII printable char (eg.
0x9B CSI
could be represented in a 7-bit environment as 0x1B 0x5B
␛ [: this is the start of ANSI
terminal control sequences). Since they were redundant, those control
chars were hardly used. Indeed Windows-1252 decided to extend ISO 8859-1
by reassigning those codepoints. Still according to Wikipedia,
U+008E SS2 and
U+008F SS3 in EUC-JP
are amonsgt the few C1 control codes used in their intended usage, besides
round-trip to EBCDIC.
Further, U+0080 PAD,
U+0081 HOP and
U+0099 SGC
are marked as figment
, meaning
labels
for C1 control code points which were never actually approved in any
standard
, which I suppose means they're even more obscure; see
also this
posting by Ken Whistler.
The ISO/IEC 8859-1:1997
document does not give any meaning to codepoints
0x80–0x9f, deferring their meaning to ISO/IEC
6429.
For HTML5, ISO 8859-1 is aliased to Windows-1252. It wouldn't make sense to use the C1 control charactes in an HTML document.
In summary and in conclusion, the C1 controls included in the tables for ISO 8859-X are an obscure relic of computer history. If you have data that uses those codepoints, in all likelihood it is actually using Windows-1252 or another extension of ISO 8859-1.
The DOS CP encodings are shown with C0 control characters in the
0x00–0x1f range. This follows
the
Unicode translation tables. Other sources (eg.
Wikipedia's CP437 page)
show the graphical characters instead. A SO answer goes into some
details about the interpretation of that range.