Un valor UTF32 válido se encuentra entre 0x000000 y 0x10ffff, ambos incluidos, y no debe incluir valores de punto de código suplentes (0x00d800 ~ 0x00dfff).
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English version
A valid UTF32 value is between 0x000000 and 0x10ffff, inclusive, and should not include surrogate codepoint values (0x00d800 ~ 0x00dfff).
.Net Framework