UTF-8, a transformation format of Unicode and ISO 10646

摘要

The Unicode Standard, version 1.1, and ISO/IEC 10646-1:1993 jointlydefine a 16 bit character set which encompasses most of the world'swriting systems. 16-bit characters, however, are not compatible withmany current applications and protocols, and this has led to thedevelopment of a few so-called UCS transformation formats (UTF), eachwith different characteristics. UTF-8, the object of this memo, hasthe characteristic of preserving the full US-ASCII range: US-ASCIIcharacters are encoded in one octet having the usual US-ASCII value,and any octet with such a value can only be an US-ASCII character.This provides compatibility with file systems, parsers and othersoftware that rely on US-ASCII values but are transparent to othervalues.