You can actually overlay any two characters this way (with an optional vertical adjustment), so there are other creative ways you can use this.
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@bj there's actually a word for this, as it was used commonly with typewriters (where hitting backspace didn't delete the character, just moved the paper back a space): https://en.wikipedia.org/wiki/Overstrike?useskin=vector
-F
@Felthry Yeah, and I've always admired the Unix-standard "Compose" key and liked the idea of just combining characters together. Also, the old PLATO systems (which pioneered a whole lot of things that were later reinvented) had this kind of overstrike thing and they even used it for emoticons.