Currently there is a major problem with how formatting / superblanks interacts with word/chunk reordering in Apertium.
If the input is
<a id="foobar" href="http://example.com">Foo<b>bar</b>.</a>
and we want to reorder the words, we currently only reorder the words, and don't touch (or even look at) the blanks, since we don't want to mess up the html, so the output becomes
<a id="foobar" href="http://example.com">Бар<b>фоо</b>.</a>
but now the bold has shifted from source word "bar" to the target word that was "foo" in the input.
All language pairs either do this, or have a possibility of messing up the format:
$ echo '<i>Perro</i> <b>blanco</b>' |apertium es-en -f html <i>White</i> <b>dog</b>