Definition from the Unicode standard (4.0): "Deprecated character: A coded
character whose use is strongly discouraged. Such characters are retained in
the standard, but should not be used. Deprecated characters are retained in the
standard so that conforming data stay conformant in future versions of the
standard. Deprecated characters should not be confused with obsolete characters
which are historical. Obsolete characters do not occur in modern text, but
they are not deprecated, their use is not discouraged."