Manual unclear regarding acceptable string characters
In the section of the manual explaining variable expansion, the documentation says:
Accepted characters are unicode alphanumeric characters and _.
I have run into a couple situations where this does not appear to be accurate. Setting a string to "░▒▓█" and then
echo-ing it prints it perfectly, even though those are not alphanumeric characters. Seeing that I could do that, I then attempted to add a "@" to my string. This, however, did not work; I could not find a way to
echo a "@" either on its own or as part of a larger string. Attempting to use it within a string on its own simply terminates the string right before the "@", and
echo-ing something like "example \@ string" prints it out exactly as typed, with the "\" included. I am somewhat at a loss on how to determine which characters can be printed, and how printing them can be accomplished.