XML in a Nutshell, 3rd Edition

ISO-8859-1, Latin-1

Character sets defined by the ISO-8859 standard comprise one popular superset of the ASCII character sets. These characters all provide the normal ASCII characters from code points 0 through 127 and the C1 controls from 128 to 159. They provide different repertoires of characters in the range from 160 to 255.

In particular, many Western European and American systems use a character set called Latin-1. This set is the first code page defined in the ISO-8859 standard and is also called ISO-8859-1. Although all common encodings of Unicode map code points 128 through 255 differently than Latin-1, code points 128 through 255 map to the same characters in both Latin-1 and Unicode. This situation does not occur in other character sets.

C1 controls

All ISO-8859 character sets begin with the same 32 extra nonprinting control characters in code points 128 through 159. These sets are used on terminals like the DEC VT-320 to provide graphics functionality not included in ASCII—for example, erasing the screen and switching it to inverse video or graphics mode. These characters cause severe problems for anyone reading or editing an XML document on a terminal or terminal emulator.

Fortunately, these characters are not necessary in XML documents. Their inclusion in XML 1.0 was an oversight. They should have been banned like the C0 controls. Unfortunately, many editors and documents incorrectly label documents written in the Cp1252 Windows character set as ISO-8859-1. This character ...