Why once 'umlaut+black rectangle' and once '?+?'

[Tim]

Allegedly, on or about 15 July 2013, Alexander Volovics sent:
> Why does the "unicode bug" get expressed in 2 different ways
> on 2 different laptops:
> 
> On a Dell Inspiron laptop as: "Schr?dinger?s Cat" (?+?)
> On a Lenovo Thinkpad as: "Schrödinger▊s Cat" (umlaut + black
> rectangle) 

Different fonts?

That's what it looks like, to me, just by what you've shown as your
examples.  Both techniques have been used by computers, over many years,
and various computer systems, to indicate that there's a character that
they can't currently display, perhaps because the font lacks any glyph
drawn in it for that code, or that the text contains character
references that went beyond the repertoire supported by the current
encoding scheme (e.g. like trying to use character 240, which requires
8-bit data, in an encoding scheme that only used 7-bits).

-- 
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Linux 3.9.8-100.fc17.x86_64 #1 SMP Thu Jun 27 19:19:57 UTC 2013 x86_64

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