Nice although I think the ASCII comma feels wrong as part of a filename even if for purely aesthetic reasons.

If we want to stay within (lowercase) alphabetic Latin characters I think prefixing with the least common letters or bigrams that start a word (x, q, y, z, j) is best.

`y' for instance only autocompletes to `yes' and `ypdomainname' on my path.

Choosing a unique bigram is actually quite easy and a fun exercise.

And we can always use uppercase Latin letters since commands very rarely use never mind start with those.

Its some what natural to german spkrs who use a special set of double quotes to start a quote in print.