[For standards experts only: what is the relationship
between USASCII and ISO-646 ?
ASCII is a national (US) variant of ISO 646.
US-ASCII of MIME is something related to ASCII. It is used to
denote a MIME charset. Though it's strict definition is unclear,
people think ISO-2022-JP is not US-ASCII.
I note in my copy of ISO-
646-1983, paragraph "4.1 c) Code extension control
characters", the following: "Procedures for the use of the
code extension control characters are specified in ISO
2022."]
which means that, even in the most strict sense of terminology,
escape character is a valid character of ASCII and use of escape
seqences of ISO 2022 is conformant to ASCII.
Masataka Ohta