We've already seen the remarkable communication abilities of the Queen's handbag, but we're far from done with the wordless communication skills the Royals possess. We imagine that these tips and tricks have been handed down from generation to generation, becoming sneakier and more sophisticated all the time. This one involves cutlery.
Royals are human, and as such may be required to leave the room during a long meal to answer a call of nature. This is a quandary for staff, as to fail to collect a Royal's plate if they no longer require it would be insulting. To assist, a Royal will either cross their cutlery on the plate to indicate they're still eating or position the cutlery at an angle on the lower-right of the plate to indicate that it can be taken away. Sadly, we don't know how this works if they're eating pizza with their hands.