VNI Encoding (Windows/Unix) The VNI Encoding uses up to two bytes to represent one
Vietnamese vowel character, with the second byte supplying additional
diacritical marks, therefore removing the need to replace control characters with Vietnamese characters, a problematic system found in TCVN1 (
VSCII-1) and in
VISCII, or using two different
fonts such as is sometimes employed for TCVN3 (
VSCII-3), one containing lowercase characters and the other uppercase characters. A similar approach is taken by
Windows-1258 and VSCII-2. This solution is more
portable between different versions of Windows and between different
platforms. However, due to the presence of multiple characters in a file to represent one written character increases the file size. The increased file size can usually be accounted for by
compressing the data into a file format such as
ZIP. The VNI encoding was used extensively in the south of Vietnam, and sometimes used overseas, while
TCVN 5712 was dominant in the north. Points
0x00 through 0x7F follow
ASCII.
VNI Encoding for Macintosh A version intended for use on Macintosh systems, with a different arrangement (corresponding to the different arrangement between
Windows-1252 and
Mac OS Roman).
VNI Encoding for DOS The VNI encoding for use on DOS does not use separate characters for diacritics, instead replacing certain ASCII punctuation characters with tone-marked uppercase letters (compare
ISO 646).
VIQR and VNI-Internet Mail The use of
Vietnamese Quoted-Readable (VIQR), a convention for writing in Vietnamese using ASCII characters, began during the
Vietnam War, when
typewriters were the main tool for
word processing. Because the
U.S. military required a way to represent Vietnamese scripts accurately on official documents, VIQR was invented for the military. Due to its longstanding use, VIQR was a natural choice for computer word processing, prior to the appearance of VNI,
VPSKeys,
VSCII,
VISCII, and Unicode. It is still widely used for information exchange on computers, but is not desirable for design and layout, due to its cryptic appearance. VIQR's main issue was the difficulty of reading VIQR text, especially for inexperienced computer users. VNI created and released a free font called
VNI-Internet Mail, which utilized a variant of the VIQR notation and VNI's
combining character technique to give VIQR text a more natural appearance by replacing certain ASCII punctuation with combining characters. The following table compares VNI-Internet Mail to other codified VIQR or VIQR-like conventions. ==See also==