C Multibyte character encoding
 

1. Are there any known multibyte encodings (any encoding, not just those used in Linux/Unix) which use characters in the portable C character set as
1) the first byte of a shift byte sequence (for encodings with shift states) OR
2) the first byte of a multibyte char (for encodings without shift states)?

2. ISO 9899:1999 (Standard C specs) says,
"While in the initial shift state, all single-byte characters retain their usual interpretation and do not alter the shiftstate."

Does this mean that the portable character set (single byte characters) must have the same representation (bit pattern) while in the initial shift state of a arbitry locale as they did while in the default "C" locale?

3. Are there restrictions to the kind of encodings that can be used by locales in Linux? eg Does a multibyte encoding which has ascii '/' as part of a multibyte sequence allowed to be used in Linux locales?

ps: to moderators/ site owner -can we have another forum dedicated to Linux i18n?