US-ASCII
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... using only octets with the high-order bit clear (7 bit US-ASCII
values, [US-ASCII]), and is thus deemed a mail-safe encoding ...
... UTF-8, the object of this memo, uses all bits of an
octet, but has the quality of preserving the full US-ASCII range:
US-ASCII ...
... US-ASCII range:
US-ASCII characters are encoded in one octet having the normal US-
ASCII value, and any octet with such a value can only stand for an
...
... ASCII value, and any octet with such a value can only stand for an
US-ASCII character, and nothing else.
...
... Character values from 0000 0000 to 0000 007F (US-ASCII repertoire)
correspond to octets 00 to 7F (7 bit US-ASCII ...
... US-ASCII repertoire)
correspond to octets 00 to 7F (7 bit US-ASCII values). A direct
consequence is that a plain ASCII string is also a valid ...
... file systems
or other software (e.g. the printf() function in C libraries) that
parse based on US-ASCII values but are transparent to other
values.
...