Queen Elizabeth.Photo: PA

Queen Elizabeth II meeting patient Pat White during a visit to officially open the new building at Thames Hospice

There’s alot of protocolto follow when meetingQueen Elizabeth— and maybe silencing your phone should be added to the list!

When the Queen, 96, and Princess Anne made asurprise appearanceon Friday to open the new 28-bedThames Hospicebuilding, the monarch was introduced to patient Pat White and her husband. But just as the husband and Queen started to shake hands after being introduced, his phone started ringing. He hurried to take it out of his suit pocket and end the call.

The Queen appeared to address the potentially awkward moment lightheartedly.

“They are lovely,” Hurst told PEOPLE. “I wasn’t sure what they’d be like and what to call them in terms of their titles. I called them ‘Kate’ and ‘Will,’ and they were really relaxed.”

But for the record: if you should be introduced to the Queen, the correct formal address is “Your Majesty.” For any further address, you should call her “Ma’am,” pronounced with a short “a,” as in “jam.” While it’s perfectly acceptable to simply shake hands when being introduced to a royal, men may opt to do a slight neck bow (from the head only) while women do a small curtsy.

Queen Elizabeth.PA

Queen Elizabeth II during a visit to officially open the new building at Thames Hospice

Wearing a floral print dress and pearl accessories, the monarch moved around with the aide of a cane, which she has been using regularly since October due to herongoing mobility issues. And of course, she didn’t leave home without hertrusty handbagon her arm.

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Queen Elizabeth and Princess Anne.PA

Queen Elizabeth II meeting staff during a visit to officially open the new building at Thames Hospice

Friday’s outing markedQueen Elizabeth’s fourth visit to the charity. She first opened Thames Hospice in Nov. 1987. In the last few years, it has been modernized and rebuilt on a new site following a huge $26 million fundraising effort.

Thames Hospice Chair of Trustees Jonathan Jones said afterwards, “Today’s momentous visit builds upon a long-held association between the royal family and Thames Hospice. It is a huge privilege to welcome Her Majesty to officially open our facility and show how the charity continues to flourish 35 years on from the Queen’s very first visit.”

source: people.com