The options can be combined. Add zero-width marks inserts non-printing,
zero-width characters (specifically the Unicode U+200E LEFT-TO-RIGHT MARK
and U+200F RIGHT-TO-LEFT MARK characters) into the text. These are invisible,
although some editors/applications may purge them. With the Prepend every word
mode, only the LTR mark is used before each word. Use special spaces replaces
the spaces with U+2005 FOUR-PER-EM SPACE. Replace dashes replaces U+002D HYPHEN-MINUS with U+2010 HYPHEN and U+2014 EM DASH with U+2015 HORIZONTAL BAR. Add footnote on copy is
different: instead of hidden characters, it appends a visible plain-text disclosure
line to the end of the copied text.