Japan’s Agency for Cultural Affairs (文化庁) published the official revision of the Jōyō Kanji (常用漢字) set less than a week ago, on November 30, 2010. For those who are unaware, Jōyō Kanji represent the kanji in common usage in Japan, and this set now includes 2,136 kanji. The 2010 revision is significant for several reasons, and I will briefly explore them in this post.

First, the last time that the Jōyō Kanji set was touched was in 1981, nearly thirty years ago. 95 kanji were added at that time, bringing the total number of kanji to 1,945. Prior to the 1981 revision, this kanji set was called Tōyō Kanji (当用漢字), and included 1,850 kanji.

Second, 196 kanji were added in the 2010 revision. There are three noteworthy things about these additional kanji:

1. Four of the 196 kanji are outside the scope of JIS X 0208:1997, but are otherwise included in JIS X 0213:2004. From a practical perspective, this means that some Japanese fonts, specifically those that support only JIS X 0208, may not include glyphs for four of the 196 additional kanji.
2. One of those four kanji is in CJK Unified Ideographs Extension B. From an implementation perspective, this means that it is encoded outside Unicode’s BMP (Basic Multilingual Plane). Implementations that support only BMP code points are thus inadequate regardless of whether the selected font includes its glyph.
3. Several of the kanji are in the traditional (unsimplified) form, which breaks the long-standing convention that Jōyō Kanji are in the simplified form, which sometimes amounts to the mere use of simplified radicals or components. The figure below exemplifies this by showing that the newly-added kanji use the traditional form of Radical #162 (辶; its simplified form has one less stroke: 辶), either as the radical or as a component.

Third, five kanji were removed. There is a potential issue or concern related to removing kanji, specifically that all Jōyō Kanji are permitted to be used for personal names. As I mentioned in the December 3, 2010 CJK Type Blog post, it would be very appropriate, and perhaps prudent, for Japan’s Ministry of Justice (法務省) to grandfather the “permitted to be used for personal names” status of these five kanji by adding them to the Jinmei-yō Kanji (人名用漢字) set.

Also, related to the Jinmei-yō Kanji set, I identified 129 of the 196 kanji being added to Jōyō Kanji as already being among its 985 kanji, and can thus be removed to avoid duplication between the two sets of kanji. If we were to remove these 129 kanji, and grandfather the five kanji that were removed from Jōyō Kanji, the result is 861 kanji.

To help readers better understand the details of the 2010 Jōyō Kanji revision, I prepared a table that shows the 196 kanji that were added, and the five that were removed, along with their JIS X 0213 code points, Unicode scalar values, and Adobe-Japan1-6 CIDs. The 129 kanji that are identical to those in the Jinmei-yō Kanji set have been highlighted in cyan, the four kanji that are outside the scope of JIS X 0208 have been outlined, and the one that is in Extension B has been highlighted in gray.

As a final note, I’d like to state my happiness that two specific kanji are now among those in Jōyō Kanji: 藤 and 瑠. Why does this make me so happy? My daughter’s full name, 工藤瑠美, can now be expressed using Jōyō Kanji. ☺