Denshi Jisho uses the Edict and Kanjidic2 dictionaries, provided by the Electronic Dictionary Research and Development Group at Monash University. The SKIP codes for kanji are derived from the Kodansha Kanji Learner's Dictionary by Jack Halpern. Jack Halpern also holds the copyright for the kanji frequency information, the New Japanese-English Character Dictionary numbers and Kodansha Kanji Learner's Dictionary numbers. Please see the data and copyright information for more details.