Unicode allows you to write any symbol in use in the world, and if one is somehow missing from Unicode, it'll get added in a future version of the specification. Right?

Here's a symbol we all know well: ￿
Aka, "box with 4 small F's in it".

But that's not the only such symbol, there was a whole class of them in common use in the early 2000's, so common that they were called "tofu" when grouped together.

Modern unicode systems cannot display those historical characters!

Clearly this needs to be fixed with an extension to the Unicode standard. I propose TOFU, a combining character that makes whatever it's combined with be displayed as a font fallback box glyph containing its Unicode code point.