Harrod's is an upscale department store in London. It lets all sorts of people inside, including riff raff like you and me. If you contact the staff online, they'd like to know how to address you. They wouldn't want to refer to a Wing Commander as a Princess or a Sheikh as Her Royal Highness. That's why the online contact form requires that you provide your title.
-via Marilyn Terrell, who says, "I prefer Viscountess." How about you?