from
The Free On-line Dictionary of Computing (8 July 2008)
Supplementary Ideographic Plane
<text, standard> (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://unicode.org).
(2002-06-19)