Mapping from GB 12345-90 to GB 2312-80

In almost all cases, for each codepoint in GB 2312-80, the corresponding codepoint in GB 12345-90 contains the most common traditional form of the GB 2312-80 character, so that the mapping of characters in levels 1 and 2 is trivial.

The exceptions are three instances where GB2312-80 includes (in level 2) a traditional form corresponding to a simpler character in level 1. In each of these cases, the simpler character was a rare character that was substituted for a common character with more strokes. In GB 12345-90, these pairs are interchanged, so that the more common traditional form occurs in level 1. In mapping from GB 12345-90 to GB 2312-80, both forms should be mapped to the simplified form in level 1:

    1-6565 -> 0-2683    # hou4 "empress" vs. "behind"
    1-6637 -> 0-5164    # yu2 "I, me" vs. "remainder"
    1-8765 -> 0-3520    # yao1 "one, small" vs. me5 (question particle)

GB 12345-90 also adds a level 3, containing additional variants (103) of some level 1 characters used in the traditional orthography. Their level 1 counterparts are:

    1-8801 -> 0-1658    1-8836 -> 0-2910    1-8871 -> 0-4165
    1-8802 -> 0-1669    1-8837 -> 0-3001    1-8872 -> 0-4285
    1-8803 -> 0-1777    1-8838 -> 0-3061    1-8873 -> 0-4341
    1-8804 -> 0-1780    1-8839 -> 0-3077    1-8874 -> 0-4353
    1-8805 -> 0-1823    1-8840 -> 0-3143    1-8875 -> 0-4408
    1-8806 -> 0-1837    1-8841 -> 0-3168    1-8876 -> 0-4408
    1-8807 -> 0-1907    1-8842 -> 0-3207    1-8877 -> 0-4408
    1-8808 -> 0-1969    1-8843 -> 0-3215    1-8878 -> 0-4419
    1-8809 -> 0-1983    1-8844 -> 0-3216    1-8879 -> 0-4531
    1-8810 -> 0-1986    1-8845 -> 0-3259    1-8880 -> 0-4537
    1-8811 -> 0-2117    1-8846 -> 0-3279    1-8881 -> 0-4582
    1-8812 -> 0-2119    1-8847 -> 0-3290    1-8882 -> 0-4721
    1-8813 -> 0-2177    1-8848 -> 0-3317    1-8883 -> 0-4721
    1-8814 -> 0-2212    1-8849 -> 0-3343    1-8884 -> 0-4744
    1-8815 -> 0-2223    1-8850 -> 0-3417    1-8885 -> 0-4782
    1-8816 -> 0-2281    1-8851 -> 0-3462    1-8886 -> 0-4875
    1-8817 -> 0-2302    1-8852 -> 0-3525    1-8887 -> 0-5009
    1-8818 -> 0-2322    1-8853 -> 0-3541    1-8888 -> 0-5022
    1-8819 -> 0-2365    1-8854 -> 0-3541    1-8889 -> 0-5184
    1-8820 -> 0-2420    1-8855 -> 0-3541    1-8890 -> 0-5189
    1-8821 -> 0-2441    1-8856 -> 0-3554    1-8891 -> 0-5185
    1-8822 -> 0-2540    1-8857 -> 0-3570    1-8892 -> 0-5224
    1-8823 -> 0-2546    1-8858 -> 0-3579    1-8893 -> 0-5238
    1-8824 -> 0-2567    1-8859 -> 0-1757    1-8894 -> 0-5264
    1-8825 -> 0-6756    1-8860 -> 0-3827    1-8901 -> 0-5402
    1-8826 -> 0-2690    1-8861 -> 0-3830    1-8902 -> 0-5427
    1-8827 -> 0-2714    1-8862 -> 0-3843    1-8903 -> 0-5427
    1-8828 -> 0-2756    1-8863 -> 0-3845    1-8904 -> 0-5434
    1-8829 -> 0-2767    1-8864 -> 0-3851    1-8905 -> 0-5438
    1-8830 -> 0-2781    1-8865 -> 0-3907    1-8906 -> 0-5454
    1-8831 -> 0-2802    1-8866 -> 0-3909    1-8907 -> 0-5476
    1-8832 -> 0-2824    1-8867 -> 0-4743    1-8908 -> 0-5494
    1-8833 -> 0-2850    1-8868 -> 0-3979    1-8909 -> 0-5528
    1-8834 -> 0-2859    1-8869 -> 0-3990
    1-8835 -> 0-2886    1-8870 -> 0-4023

Since the most common traditional counterpart occurs in the position of each GB 2312-80 character, in some cases a GB 2312-80 character has been moved to level 3, while the original position is occupied by a more complex character.


Part of Notes on CJK Character Codes and Encodings.