Microsoft Excel -> application/vnd.ms-excel
CSV is a text format, xls[x], json, and (mostly) xml are not.
printf "alice\007london\007uk\nbob\007paris\007france\n" > data.bsv
ding! ding! ding! winner winner, chicken dinner!
Although BEL would drive me up the wall if I broke out any of my old TTY hardware.
0x1C - File Separator
0x1D - Group Separator
0x1E - Record Separator
0x1F - Unit Separator
So I guess 1F would be the "comma" and 1E would be the "newline."
I am pretty sure you shifted the meaning, the decimal separator is part of the atomic data it does not need a control character.
You would use 1F instead of the comma/semicolon/tab and 1E to split lines (record means line just like in SQL).
You could then use 1D to store multiple CSV tables in a single file.
This would confuse most users of csvs they are not programmers they at most use text editors and Excel.
By the way, RS is decimal 30 (not octal '\030'). In octal, RS is '\036'. For example:
$ printf '\036' | xxd -p
1e
$ printf '\x1e' | xxd -p
1e