This usually indicates that the document originated in WordPerfect and the
WP Typographic Symbols font was used for apostrophes, quotes, dashes, and
the like. A simple solution for local documents is to install the font
(though the WP symbols are rather ugly and the same regardless of what font
you're using), but the document will not be portable (if you send it to
someone who doesn't have the font installed, the recipient will see =, @, A,
etc.), so the only permanent solution is to replace the =, @, etc., with the
appropriate characters in the default paragraph font.