>(5) Xi and Chi: There being no single Roman letter for "Xi"
>other than X, the "look-alike" use of X for "Chi" is confusing,
>though some use it. And some seem to like to use C for "Sigma."
>Since S is otherwise unused, and poses no confusion whatever,
>using C for "Sigma" makes for problems in decoding back to Greek,
>especially since it is the only letter available for "Chi"
>(unless X is used, thus posing a problem for "Xi").
Given the "look-alike problem" (i.e. "X" as Xi/Chi) might it be useful to
use "3" for Xi. This has the virtue of also being a rough "look-alike" (at
least in the right font) without the possiblility of confusion.
(On a similar note, we might suggest "8" for Omega, although "Q" has no
similar problem of confusion.)
firstname.lastname@example.org "KAI hO LOGOS SAR3 EGENETO...."