资料来源 : Free On-Line Dictionary of Computing

Supplementary Ideographic Plane
     
         (SIP) The third plane (plane 2) defined in
        {Unicode}/{ISO 10646}, designed to hold all the {ideographs}
        descended from Chinese writing (mainly found in Vietnamese,
        Korean, Japanese and Chinese) that aren't found in the {Basic
        Multilingual Plane}.  The BMP was supposed to hold all
        ideographs in modern use; unfortunately, many Chinese dialects
        (like Cantonese and Hong Kong Chinese) were overlooked; to
        write these, characters from the SIP are necessary.  This is
        one reason even non-academic software must support characters
        outside the BMP.
     
        {Unicode home (http://www.unicode.org)}.
     
        (2002-06-19)