0x1C FS File Separator
0x1D GS Group Separator
0x1E RS Record Separator
0x1F US Unit Separator
You just need a font with glyphs for them.https://en.wikipedia.org/wiki/Delimiter#ASCII_delimited_text
\ is AltGr+?
] is AltGr+9
^ is Shift+^, then space
_ is Shift+-
AltGr is the right Alt key, to the right of the space bar.So none of those are single keys, which means that combining them with Ctrl to write control characters becomes almost comically difficult. Not very accessible to typical users, I'd say.
P.S. Aren't .xlsx files subject to the same problem as the .csv?
It does have similar "executability" issues as CSV (and more), but 1. the formula evaluation is documented and expected behavior, 1b. there is a documented way to suppress it, and 2. programs reading it are aware that security is a thing, and either a) constrain/sandbox it (in the case of table processors such as MSOffice or LibreOffice), or b) don't execute its macros and expansions at all (in the case of libraries such as PhpExcel). Not sure about the Google Docs issue.
(As far as "common knowledge" - knowledge for manual inspection of strings is IMNSHO not required, all that's needed is that it's program-readable; in this respect, most table processors are capable of this. The point "but you can inspect CSVs by hand" comes from experience: it is also possible to inspect binaries by hand, neither of these is intuitive, both are a learned skill)