SKIP Codes


Jack Halpern (

Ever since my New Japanese-English Character Dictionary (NJECD) came out (Kenkyusha 1990, NTC 1993), I have been getting inquiries asking for permission to use SKIP (System of Kanji Indexing by Patterns) data in software products and electronic dictionaries. Below I explain the policy of the Kanji Dictionary Publishing Society (KDPS) on how to use copyright issues when distributing SKIP data or using it in software product or electronic dictionary.


Briefly, SKIP is an indexing system that enables the user to locate kanji quickly and accurately. The system is extremely convenient because it can be learned in a very short time, is easy to use, and requires very little prior knowledge of kanji.

The central idea of SKIP is the classification of characters into four major categories on the basis of easy-to-identify geometrical :

  1. Left-right

  2. Up-down

  3. Enclosure

  4. Solid

Characters belonging to the first three categories are arranged in ascending order of hyphenated numerals that represent the number of strokes in the and the number of strokes in the See and NJECD front matter for details.

To distribute SKIP data within a group or use it in a commercial or non-commercial product, please confirm that you agree to the following conditions:


    SKIP data is protected by copyright, copyleft and patent laws. The copyright holder is Jack Halpern, chief editor of KDPS (the Kanji Dictionary Publishing Society). The SKIP data must be protected from illegal copying and distribution, using such measures encryption. The data must be encrypted if it is to be used in any kind of product, including commercial products, software and freeware. The data, or extracts from it, must not be distributed to a third party, must not be sold as part of any commercial software package, and must not be incorporated in any published dictionary or other printed document without the specific permission of the copyright holder.


    The source of SKIP data shall be acknowledged in the information screens of the product, and the following disclaimer should appear in the documentation and/or help screens:

    "SKIP (System of Kanji Indexing by Patterns) numbers are derived from the New Japanese-English Character Dictionary (Kenkyusha 1990, NTC 1993) and The Kodansha Kanji Learner's Dictionary (Kodansha International, 1999). SKIP is protected by copyright, copyleft and patent laws. The commercial or non-commercial utilization of SKIP in any form is strictly forbidden without the written permission of Jack Halpern, the copyright holder. Such permission is normally granted. Please contact and/or see"


    SKIP is a product of seven years of computer-assisted research and experimentation on how kanji elements are intuitively perceived in terms of their parts. Development work was financed by private funds and research grants. To enable us to continue to develop useful data and products, we ask for you cooperation by paying KDPS (the Kanji Dictionary Publishing Society) a royalty 0.5% (negotiable) if you are using the data for a commercial product. Depending on the circumstances, it is also possible to use SKIP data free of charge or at a lower royalty.

    Finally, please send a copy of your product to Jack Halpern