Mystery character in PM

[Sir Osis of Liver]

A german forum pm'd login credentials for host account.  Password includes english alpha/numeric characters, and a '?'.  If I type the password manually, or copy it from Notepad, it fails.  If I copy it from pm, it works.  Apparently the '?' is actually a diacritic letter, which is not displayed correctly in pm because this forum is not running german utf-8, but it copies correctly from pm.  How does that work?

[Arantor]

The ? indicates one of two things: either a malformed character or a character glyph in a font you don't have installed.

As for 'German UTF-8', this forum is installed with UTF-8 just fine and has been for years. It doesn't require you viewing it in the 'correct' language pack for it to be a thing.

As for why it fails if you type it directly, you're probably typing the wrong character (a literal ? is not the right one) and copying it to Notepad will shift it to a different encoding, probably Win-1252 (unless you've told Notepad to not treat it as such). If in doubt, save the PM page as is and examine the individual bytes with a hex editor to see what it is.

[Sir Osis of Liver]

If the browser is not able to display the character correctly, then I shouldn't be able to copy it from the pm, because the browser has substituted a ? for that character.  I can see the umlauts in Götterdämmerung, copy it to Notepad, and it displays them correctly.

[Arantor]

Just because the browser can't display it for some reason, doesn't mean it isn't aware of what the bytes are.