mojibake text
Mojibake (literally "character transformation") is the term for gibberish resulting from wrong encoding being applied to non-ASCII text. Sometimes, if the font is lacking appropriate glyphs, a substitute character might be shown (such as blank box, or particularly egregious, a ? in Microsoft products, making it extra-hard to notice that something is missing in small snippets).
The following tags are aliased to this tag: mojibake (learn more).