Hi Aaron, great work there, thanks.

Just a minor, pedantic, addition: I have added the following lines in functions.php because acronym and strike are not valid HTML5 tags.

(functions.php may be the wrong place, but it seemed to do the job, and quite frankly, I don’t care :-)

unset( $allowedposttags['acronym'] );
unset( $allowedtags['acronym'] );
unset( $allowedposttags['strike'] );
unset( $allowedtags['strike'] );