In some (rare) typefaces you'll see a slash through the character for the number zero. In even fewer cases you might see a slash through other digits, such as seven. Is there a name for this slash?
If it were a pronunciation-modifier it might be called a diacritic, and if it were additional marks on the end of some glyphs it might be called a serif, but these descriptions don't fit the slash on digits.
I looked at the Wikipedia article Slashed Zero, but even that didn't actually have a word for the mark.