JIS X 0208

Except when there is prior agreement among the relevant parties, characters (gaiji) for information interchange should not be assigned to the unassigned code points.

Furthermore, when assigning characters to unassigned code points, it is necessary to be cautious of unification in regards to kanji glyphs.

For example, row 25 cell 66 corresponds to the kanji meaning "high" or "expensive"; both the form with a component resembling the "mouth" character (口) in the middle (高) and the less common form with a ladder-like construction in the same location (髙) are subsumed into the same code point.

For example, both the character at ISO/IEC 646 International Reference Version (US-ASCII) column 4 line 1 and the one at JIS X 0208 row 3 cell 33 have the name "LATIN CAPITAL LETTER A".

As to the cause of how these numerals, Latin letters, and so forth in the kanji set are the "full-width alphanumeric characters" (全角英数字, zenkaku eisūji) and how the original implementation came forth with a differing interpretation compared to the IRV, it is thought that it is due to these incompatibilities.

Ever since the first standard, it has been possible to represent composites (合成, gōsei) such as encircled numbers, ligatures for measurement unit names, and Roman numerals;[10] they were not given independent kuten code points.

For this reason, it became disallowed to represent Latin characters with diacritics at all, with possibly the sole exception of the ångström symbol (Å) at row 2 cell 82.

The katakana wi (ヰ) and we (ヱ) (both obsolete in modern Japanese) as well as the small wa (ヮ), not in JIS X 0201, are also included.

For example, in level 2, right after row 49 cell 88 (劍), the immediately following characters deviate from the general rule (stroke count in this case) to include three variants of 49-88 (劔, 劒, and 剱).

It was confirmed that no original text for the "Japanese Personality Registration Name Kanji" referenced in the "Correspondence Analysis Results" exists.

For the "National Administrative District Listing", Sasahara Hiroyuki of the fourth version's drafting committee examined the kanji that appeared on the in-progress development pages for the first standard.

The committee also consulted many ancient writings, as well as many examples of personal names in a database of NTT phone books.

Due to this thorough investigation, the committee was able to pare down the number of kanji for which the source cannot be confidently explained to twelve, shown on the adjacent table.

A shadow from that process was misinterpreted as a line, resulting in 妛 (a picture of this can be found in the Jōyō kanji jiten).

For a single glyph, there exist an endless range of possible concretely and/or visibly different character forms.

A variation between a character form of one glyph is termed a "design difference" (デザインの差, dezain no sa).

Also, the unification criteria need only be used for generally used kanji and for the purpose of assigning things to the code points of this standard.

The standard requests that generally unused kanji not be created based on the example glyphs and unification criteria.

For example, for the purpose of backwards compatibility, it is permitted to consider 10/3 12/1 in International Reference Version + 8-bit code for kanji to correspond to a full-width "A".

If the kanji set is used along with ASCII or JIS-Roman, then even if the standard is abided by strictly, the unique encoding of a character is not guaranteed.

Entrusted by the Agency of Industrial Science and Technology, a JIPDEC kanji code standardization research and study committee produced the draft.

The draft of the second standard was based on the consideration of factors such as the promulgation of the jōyō kanji, the enforcement of the jinmeiyō kanji, and the standardization of Japanese-language Teletex by the Ministry of Posts and Telecommunications; also, the next modification was performed to keep pace with JIS C 6234-1983 (24-pixel matrix printer character forms; presently JIS X 9052).

There were many smaller changes away from the Kangxi-style variants; for example, row 25 cell 84 (鵠) lost part of a stroke.

The difference in form for the examples noted above ("鵠" and "靠") falls under the parameters for unification criterion 42 (concerning the component "告").

However, for 29 code points (such as the problematic 18-10 and 38-34 mentioned above), the forms inherited by the fourth standard contradicts the original intent of the first.

Entrusted by the AIST, a JSA committee for research and study of coded character sets produced the draft.

The basic policies of this revision were to perform no changes the character set, to clarify ambiguous provisions, and to make the standard relatively easier to use.

[18] The character meanings and selection rationales were not properly documented, making it difficult to identify whether desired kanji corresponded to those in its repertoire.

According to this standard, it is "designed with the goal being to offer a sufficient character set for the purposes of encoding the modern Japanese language that JIS X 0208 intended to be from the start.

For example, the glyph at row 33 cell 46 of JIS X 0208 ("僧", described above) unifies a few variants due to its right-hand component.