ARIB STD B24 character set

ARIB STB-B24 Kanji set

Weather symbols: a few of the extended symbols included.
Language(s)	Japanese, English, Russian Partial support: Greek, Chinese
Standard	ARIB STB-B24 Volume 1
Classification	ISO-2022-structured CJK DBCS
Extends	JIS X 0208
Encoding formats	ARIB STB-B24 encoding (ISO 2022 based) Shift JIS (ARIB variant)[1]
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Volume 1 of the Association of Radio Industries and Businesses (ARIB) STD-B24 standard for Broadcast Markup Language^[2] specifies, amongst other details, a character encoding for use in Japanese-language broadcasting. It was introduced on 1999-10-26.^[2] The latest revision is version 6.3 as of 2016-07-06.

It includes a number of ARIB extended characters (ARIB外字, ARIB gaiji) not found in the base standards (JIS X 0208 and JIS X 0201). It was the source standard for many symbol characters which were added to Unicode, including portions of the Miscellaneous Symbols, Enclosed Alphanumeric Supplement and Enclosed Ideographic Supplement blocks.^[3] Its contributions partially overlap the Unicode emoji, but were added a year earlier, in Unicode 5.2.^[4]

Fascicle 1 of the ARIB STD-B62 standard, published in 2014, defines Unicode mappings for a selection of the B24 extended characters (excluding, for example, those duplicated by JIS X 0213), as well as a few extended Kanji.^[5] It also includes a mapping of utilised characters outside the Basic Multilingual Plane to the BMP's private use area.

Sets and codes[]

The ARIB STD B24 standard defines multiple character sets and a method of switching between them. These include a Kanji set (an extension of JIS X 0208), an Alphanumeric set, a Hiragana set, Katakana sets of two distinct layouts and four mosaic sets.^[6] The sets are selected using ISO 2022 mechanisms for 94-sets, using the following codes (proportional sets use the same layout as the corresponding non-proportional ones):^[7]

Code charts[]

Kanji (double-byte) set[]

This is a double-byte character set extending JIS X 0208.

Lead byte[]

The encoding bytes correspond to the row or cell number plus 0x20, or 32 in decimal (see below). Hence, the code set starting with 0x21 has a row number of 1, and its cell 1 has a continuation byte of 0x21 (or 33), and so forth. Most of the code corresponds to JIS X 0208, exceptions are shown with a heavy border.

Character sets 0x21-0x74 (row numbers 1-84: punctuation, alphabets, numbers, Kana, Kanji)[]

Character set 0x7A (row number 90, traffic symbols)[]

Characters 90-45 through 90-63 and 90-66 through 90-84 (shown below with a heavy border) are listed in the B24 standard only in table 7-10 (the list of extension characters), and are also the only characters in rows 90 through 91 which are not transport-related symbols; this is noted in the B24 standard in an endnote to table 7-10.^[10] The remainder of the extensions are listed in both table 7-4 (the double-byte code chart) and table 7-10.^[10]