AIX Version 4.3 Differences Guide

Single-Byte Character Set Support (SBCS)
Support is limited to single-byte locales in the underlying operating
system. Bidirectional code set support is limited.
PASSTHRU
Support is limited to the ability of the product to pass data through the
program without processing. The information is handled in such a
manner that all data, control, and graphics characters flow unaltered
through the program directly to its output.
The following products and commands do not support full ILS:
• Adobe Acrobat Reader supports PASSTHRU only graphics, tplot, graph, and
spline commands.
• Netscape Navigator supports PASSTHRU only.
• NFS supports PASSTHRU only.
• NCS supports PASSTHRU only.
• TCP/IP telnet command does not support NLS.
10.3 Unicode
The Universal Coded Character Set (UCS), or Unicode (UCS-2), is a character
code designed to encode text for display and storage in computer-based files.
The UCS global character encoding was developed jointly by the computer
industry and the International Organization for Standardization (ISO) and defines
the state of the art for character handling.
The design of the Unicode standard is based on the simplicity and consistency of
today's prevalent character code set, ASCII (and Latin-1, an extended version of
the ASCII code set), but goes beyond ASCII's limited ability to encode only the
Latin alphabet. The Unicode encoding provides the capability to encode all of the
characters used by all the principle written languages throughout the world.
To accommodate the many thousands of characters used in international text, the
Universal Coded Character Set was developed and implemented in two
variations:
UCS-2 A 16-bit code
UCS-4 A 32-bit code
However, UCS-2, the 16-bit code (Unicode), has already been established as the
predominant code, while the 32-bit code is of limited practical interest. The
Unicode implementation keeps character coding simple and efficient since the
Unicode standard assigns each character a unique 16-bit value. It does not
require complex modes or escape codes to specify modified characters or special
cases.
The development of UCS on AIX Version 4.3 is based on Unicode code set
Version 2.0, which is a widely accepted standard for encoding international
character data. The AIX implementation of Unicode (UCS-2) will allow the user to
process data from any of the supported Unicode scripts and to mix and match
characters from differing language scripts within the same session.
242 AIX Version 4.3 Differences Guide