In writing a manual, I want to show examples of what a display looks like when a font doesn't have a particular character.
What Unicode character would best represent the "missing character" symbol? I have looked through the Unicode Standard but not found anything that immediately springs to mind. Since missing characters are represented by hollow squares in Arial Unicode MS, I could arbitrarily pick something like U+25A1 -- but that might not look the same (in some fonts) as the "missing character" hollow square.
