It’s unlikely you’ll meet King Charles III, monarch of Britain, his wife Queen Camilla, or any member of the royal family during their four-day state visit to the United States. But if by chance you do encounter them, how should you greet them?

There are “no obligatory codes of behavior” when meeting the king and queen, or any royal family member, says the British Royal Family website.

However, it’s best to follow the traditional forms, which can be summed up as keeping a respectable distance, bowing or curtsying, being polite, and addressing them first as “Your Majesty” and later as “Sir” or “Ma’am," as circumstances require.

Above all, don’t touch. Don’t try any physical contact, including a handshake, unless the royal initiates it.

King Charles and his entourage are in the United States from April 27-30. Here’s a quick visual guide on what to do – and what not to do, if you meet them.