SKIP - The System of Kanji Indexing by Patterns
The System of Kanji Indexing by Patterns (SKIP) system for ordering kanji was developed by Jack Halpern and used as the main index for kanji in the New Japanese-English Character Dictionary (Kenkyusha/NTC, 1990) and The Kodansha Kanji Learner's Dictionary (Kodansha, 1999) and other dictionaries published by Kanji Dictionary Publishing Society.
The SKIP codes for the kanji not in the NJECD were compiled by Jack Halpern and Martin Duerst (the remaining kanji in JIS X 0208) and Jim Breen (the 5,801 kanji in JIS X 0212).
An overview of the SKIP system is available at this page.
Conditions Of Use
As of December 12, 2014, the SKIP coding system and all established SKIP codes have been placed under a Creative Commons Attribution-ShareAlike 4.0 International. (The full License Code is here.)
As stated in that license, you may copy and redistribute the SKIP coding system in any medium or format for any purpose, even commercially, as long as you give appropriate credit. Appropriate credit must clearly attribute the system and codes to Jack Halpern, with a link to the website of the Kanji Dictionary Publishing Society at http://www.kanji.org/. Below is an example of how such an attribution may look like:
The SKIP (System of Kanji Indexing by Patterns) system for ordering kanji was developed by Jack Halpern (Kanji Dictionary Publishing Society at http://www.kanji.org/), and is used with his permission.
To get the latest SKIP codes, please contact us at jack[at]cjki.org.