It's possible to remove some of historical order from the paragraph so
that we don't have to debate who knew what when. I'd suggest instead
of:
NOTE: The term "character set" as used originally in MIME arose
with the use of US-ASCII and other 7bit and 8bit specifications
which employ a simple mapping from single octets to single
characters. The advent of multi-octet coded character sets and
switching techniques has made the situation more complex. For
example, some communities have adopted the term "character encoding"
for what MIME calls a "character set", while using the phrase "coded
character set" to denote an abstract mapping from integers (not
octets) to characters.
to say
NOTE: The term "character set" was originally used in MIME with
specifications such as US-ASCII and other 7bit and 8bit schemes
which have a simple mapping from single octets to single
characters. Multi-octet coded character sets and
switching techniques make the situation more complex. For
example, some communities use the term "character encoding"
for what MIME calls a "character set", while using the phrase "coded
character set" to denote an abstract mapping from integers (not
octets) to characters.