I will add, sometimes you want to insert a symbol that is not available in
the default font. So it may be something from a "symbol" font or a
"wingding". But autocorrect will insert the character, but only in the
default font (sigh).
If you use a symbol a lot, you can set up a separate page somewhere just to
keep together symbols in their native fonts, so at least you can find them
more easily and copy/paste them into text.