Alt-code char:
oh, no. I wouldn't know how to makes those with my keyboard. It's fairly standard alpha-numeric with a bit of !@#$^& thrown in cuz I like it.
The codes are randomly generated, but there is a scheme to them, and it's fairly deep. I ran a decoding simulation of several hundred thousand (>250,000) random codes, and not a single one of them made it thru all the checks.
It was an experiment I wanted to try, and it seems to have worked
