ISO 646

ISO 646 is an ISO standard that specifies international variants of the 7 bit ASCII character code. Since the ASCII code specified only the letters used in the English alphabet, other countries using the latin alphabet with extensions needed to create national variants of ASCII to be able to use their native languanges. Since universal acceptance of the 8 bit byte did not exist at that time, the national characters had to be made fit within the constraints of 7 bits, meaning that some of the existing ASCII characters had to be changed.

Some national variants of ASCII are:

Code National standard Country

CA CSA Z243.4 Canada

DE DIN 66003 Germany

DK DS 2089 Denmark

NO NS 4551-1 Norway

SE Sweden

Code	National standard	Country
CA	CSA Z243.4	Canada
DE	DIN 66003	Germany
DK	DS 2089	Denmark
NO	NS 4551-1	Norway
SE		Sweden

The specifics of the changes for some of these variants are given in this table:

Binary Decimal Hex ASCII DE DK/NO SE

0010 0011 35 23 # # # #

0010 0100 36 24 $ $ $ ¤

0100 0000 64 40 @ § @ @

0101 1011 91 5B [ Ä Æ Ä

0101 1100 92 5C \ Ö Ø Ö

0101 1101 93 5D ] Ü Å Å

0101 1110 94 5E ^ ^ ^ ^

0110 0000 96 60 ` ` ` `

0111 1011 123 7B { ä æ ä

0111 1100 124 7C | ö ø ö

0111 1101 125 7D } ü å å

0111 1110 126 7E ~ ß ~ ~

Binary	Decimal	Hex	ASCII	DE	DK/NO	SE
0010 0011	35	23	#	#	#	#
0010 0100	36	24	$	$	$	¤
0100 0000	64	40	@	§	@	@
0101 1011	91	5B	[	Ä	Æ	Ä
0101 1100	92	5C	\	Ö	Ø	Ö
0101 1101	93	5D	]	Ü	Å	Å
0101 1110	94	5E	^	^	^	^
0110 0000	96	60	`	`	`	`
0111 1011	123	7B	{	ä	æ	ä
0111 1100	124	7C	\|	ö	ø	ö
0111 1101	125	7D	}	ü	å	å
0111 1110	126	7E	~	ß	~	~

Later, when 8 bit characters sets gained more acceptance, the ISO-8859-1 became the preferred method of coding these variants.

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