XML documents and APIs are Unicode
Unicode encodings:
UTF-8
UTF-16 big endian
UCS-4 big endian
UTF-16 little endian
UCS-4 little endian
Non-Unicode encodings:
ASCII (subset of UTF-8)
MacRoman
Windows ANSI
Latin 1 through Latin 15
SJIS Japanese
Big-5 Chinese
K0I8R Cyrillic
Many others...