title: Why does question mark show up in web browser?
body: <p>I was (re)reading <a href="http://www.joelonsoftware.com/articles/Unicode.html" rel="nofollow">Joel's great article on Unicode</a> and came across this paragraph, which I didn't quite understand:</p>
  
  <blockquote>
    <p>For example, you could encode the Unicode string for Hello (U+0048
    U+0065 U+006C U+006C U+006F) in ASCII, or the old OEM Greek Encoding,
    or the Hebrew ANSI Encoding, or any of several hundred encodings that
    have been invented so far, with one catch: some of the letters might
    not show up! If there's no equivalent for the Unicode code point
    you're trying to represent in the encoding you're trying to represent
    it in, you usually get a little question mark: ? or, if you're really
    good, a box. Which did you get? -> �</p>
  </blockquote>
  
  <p>Why is there a question mark, and what does he mean by "or, if you're really good, a box"? And what character is he trying to display?</p>