The small HTML code starting at https://github.com/bitcoin/bitcoin/blob/master/src/qt/locale/bitcoin_en.ts#L907 is invalid (checked via http://validator.w3.org/#validate_by_input):

It has an invalid DOCTYPE, is missing the title-tag and the meta-tag is in XHTML style, which is not allowed for HTML 4.01. I did not open a pull request, as I don't want to edit the english source file and hope for an lupdate of it, which should be done before this one get's fixed.

Edit: Had to remove all HTML-code, as this breaks the layout here :-/.