1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
Charset name: SCSU
Charset aliases: (none, except for the implicit csSCSU)
Suitability for use in MIME text: No
Published Specification:
Unicode Technical Report #6
"A Standard Compression Scheme for Unicode"
http://www.unicode.org/unicode/reports/tr6/
CCS & CES: The SCSU charset is a combination of the
Unicode and ISO 10646 Coded Character Set (CCS) with
the Character Encoding Scheme (CES) specified in
the above document. It covers exactly the
UTF-16-reachable subset of ISO 10646.
SCSU can also be classified as a Transfer Encoding
Syntax (TES), but one specifically designed for
Unicode/ISO 10646.
ISO 10646 equivalency table: Same as specification.
Additional Information:
SCSU is an encoding (CES/TES) of Unicode/ISO 10646
that allows significant size reduction of text compared
to UCS Transformation formats. It approximates the size of
text that is otherwise achieved with language-specific
charsets while encoding all of Unicode (up to U-0010ffff).
SCSU is byte-based, which helps further, traditional
compression (LZW etc.).
It is stateful and uses all byte values including NUL.
CRLF may or may not be represented by 0x0d 0x0a depending
on the encoder and the text.
Encoders can be trivial by emitting one command byte (0x0f)
followed by the text in UTF-16BE. Fairly simple encoders
yield good results with average text of any length.
Decoding is simple and requires no mapping tables.
If no control characters other than NUL, TAB, CR, and LF
are used, then text in US-ASCII or ISO-8859-1 is already
valid SCSU text.
There is a Unicode signature byte sequence defined
(0e fe ff, see specification).
SCSU is of no use for applications that require a canonical
representation of text. It is not suitable for
process-internal use.
This is an intentional part of its design.
Personal & email address to contact for further information:
Markus W. Scherer
IBM Java Technology Center
10275 N. DeAnza Blvd
Cupertino, CA 95014-2237
markus.scherer@jtcsv.com
schererm@us.ibm.com
Intended usage: LIMITED USE
|
