What to expect at the coronation
The ceremony is held in Westminster Abbey. The Archbishop of Canterbury, Justin Welby, has to put a crown on Charles's head, then one on Camilla's. Charles has trimmed down the ceremony from four hours to one, with 2,000 guests instead of the 8,000-plus his mum had.
The music will help keep you awake. As part of every coronation, the choir sings Zadok the Priest, a wonderful (and loud) piece by Handel. It was composed in 1727 for the coronation of George II. There's always new music, too: for the last two coronations, there were marches by William Walton, both of them fun and exciting, but a coronation isn't the time to start dancing in the aisles. If you do get carried away, though, you're in good company. It seems that George II did the same when he heard Handel's Hallelujah Chorus from the Messiah. Feel free to sing along to the national anthem (see below).
What to wear
It's not the Oscars, so no sexy evening wear - you don't want to upstage the VIPs. Charles's coronation will be simpler than his mother's. He'll probably look more like one of the Beatles on the cover of the Sgt. Pepper album than a traditional monarch, dressed a bit like Father Christmas on his way to a drag competition.
Don't go mad when choosing your hat; the people behind you will be thankful. In the words of Jean-Paul Sartre, hell is other people. That's never more true than when they wear a big hat and sit in front of you. And if you're worried about going over budget with your outfit, wear something recycled. The royals will approve, and you'll be following Camilla's example: she'll be wearing a recycled crown.
Finally: avoid metal. You may have to go through a security scanner like the ones at the airport - so, save any medals you may have for another event and leave your official chains of office at home.
What to say
You find yourself standing next to a royal in the loos - applying lipstick next to Kate, or washing your hands next to Harry. What should you say? What should you definitely not say?
When you first meet them, call them "Your Royal Highness". After that, it's "Ma'am" or "Sir". (And remember: Ma'am rhymes with "jam".)
If you do meet Kate, say something safe, such as: "Wonderful coronation. I'm already looking forward to William's." Perhaps you should leave off that last bit.
If, after all that tea and champagne, you meet her in the loo again, don't say, "Back again? Dear, oh dear!"
Try not to say what comes naturally, which is to ask for a selfie and make fun of what everyone else is wearing. Instead, it would be good manners to show sympathy with the King. "The poor man must get so sweaty with that robe and the crown," you could say. "I bet he wishes he were Prince Andrew." No! This last bit would be tactless; it's true it was the King's brother who told us he doesn't sweat, as a result of experiences on active service as a pilot in the navy. But he shared the information when he was defending himself against claims of sexual misconduct.
What's for tea
As a representative of the people of Germany, you have been asked to join the royal tea after the ceremony.
Hopefully, there'll be a suitably cosmopolitan range of snacks on offer, and maybe something new that's been created for the occasion. Coronation chicken was a great success last time. Perhaps a recipe this time that pays tribute to the fact that both Charles and Camilla are on their second marriage: what about "divorce duck"?
But will there really be enough to eat? Even if you think you might get hungry during the ceremony, don't take any emergency sandwiches with you. The best thing to do is have a big breakfast before you set out. And don't forget to practise drinking your tea with your little finger (your "pinkie") pointing straight up in the air. Nobody does this any more, but it will gain you respect and show everyone that you have good old-fashioned standards.
What to sing: the national anthem
God save our gracious King!
Long live our noble King!
God save the King!
Send him victorious,
Happy and glorious,
Long to reign over us,
God save the King!
~
O Lord our God arise,
Scatter his enemies,
and make them fall.
Confound their politics,
Frustrate their knavish tricks,
On thee our hopes we fix,
God save us all!
~
Thy choicest gifts in store
On him be pleased to pour,
Long may he reign.
May he defend our laws,
And ever give us cause,
To sing with heart and voice,
God save the King!