For the death of Prince Philip, Duke of Edinburgh the code name was Operation Forth Bridge, and for Queen Elizabeth II, the code word was "London Bridge is down". Since Elizabeth II died at Balmoral Castle in Scotland, Operation Unicorn (Scotland) was put into effect upon her death.

The official codename for the funeral arrangements and death notification of Prince Philip, the Duke of Edinburgh, was "Operation Forth Bridge." This name follows the British Royal Family's tradition of using famous bridges for funeral plans (e.g., "London Bridge" for Queen Elizabeth II and "Menai Bridge" for King Charles III). The "Forth Bridge" refers to the iconic cantilever railway bridge in Scotland, fitting given Philip's title as Duke of Edinburgh. Upon his death on April 9, 2021, the code was activated to initiate a period of national mourning and a ceremonial royal funeral at St George's Chapel. Unlike the massive state funeral for the Queen, Philip’s plan was designed to be lower-profile in accordance with his personal wishes, focusing on his naval career and his love for the Royal Marines, while still following the strict protocols outlined in the "Forth Bridge" document.