Noting a correction is part of a larger scope of annotating something. From Wikipedia:
There is also a two-thousand-year-old character used by Aristarchus of Samothrace called the asteriskos, ※, which he used when proofreading Homeric poetry to mark lines that were duplicated. Origen is known to have also used the asteriskos to mark missing Hebrew lines from his Hexapla. The asterisk evolved in shape over time, but its meaning as a symbol used to correct defects remained.
In the Middle Ages, the asterisk was used to emphasize a particular part of text, often linking those parts of the text to a marginal comment. However, an asterisk was not always used.
Aristarchus of Samothrace was from c. 220 – c. 143 BC, so it’s been used for notation since at least then!
Literature has been using asterisks, daggers, double daggers, etc. to denote markups, notes, corrections, whatever for centuries.
This is going to sound condescending and it's not intended that way, but read a book. Not a fiction, but non-fiction. Biographies that need research, science texts on detailed subjects, psychology with many interpretations, really anything outside of a storybook.
Have fun learning, and this is not a dumb question. You're on the right track.
I don't remember * being used on IRC, mainly because it denoted other things. I'm not saying it wasn't used, merely I remember the latter. Wasn't aware that was regex, used it in bash.