== ltr-basic.xht left-ltr-ref.xht == rtl-basic.xht right-rtl-ref.xht == rtl-span-only.xht left-rtl-ref.xht == ltr-span-only.xht right-ltr-ref.xht == ltr-ib.xht left-ltr-ref.xht == rtl-ib.xht right-rtl-ref.xht == rtl-span-only-ib.xht left-rtl-ref.xht == ltr-span-only-ib.xht right-ltr-ref.xht == rtl-linebreak.xht rtl-linebreak-ref.xht != rtl-linebreak.xht rtl-linebreak-notref1.xht != rtl-linebreak.xht rtl-linebreak-notref2.xht