[whatwg] notation for typographical uncertainty

[Bil Corry]

ddailey wrote on 9/20/2009 7:43 PM: 
> I'm saying to son: "if you can't figure out what it says, type the characters you are sure about. Use '?' marks for the letters that you aren't sure about."

You might consider using the Unicode Replacement Character, which is used by Unicode to "replace an incoming character whose value is unknown or unrepresentable in Unicode":

	http://www.fileformat.info/info/unicode/char/fffd/index.htm


- Bil