Oysters, or ostreidae as they are known in curtseying circles, are on a list of foods the Royal Family is reportedly banned from eating in public.

In fact, all shellfish is banned, according to the list, which was leaked to The Sun newspaper over the weekend.

The reason? Shellfish are more likely to be iffy than other foods and the British Empire can ill afford (geddit?) the Duke or Duchess of Cambridge, or the 91-year-old Queen, missing an event due to an undercooked prawn.

While some of the items include basic common sense (Don't drink the water in the third world etc), having to skip out on beef tataki at an event at the Japanese embassy would be enough to make some people wish to remain a civilian.

According to The Sun, the Queen observes the rules fastidiously, while the younger Royals have been known to let loose and crack open a crab claw on occasion like a delinquent teenager sneaking a cigarette during a night out.

But given food trends these days, it's highly possible that shellfish is too passe to be served at most functions, except the very top end of town (or at the David Jones launch if you happen to be spruiking your new Neil Perry-designed food venture).

Local caterers contacted by Fairfax media said that royal edicts aside, there were many conventions and customs for feeding large crowds.

Matthew Haigh, the newly-appointed executive chef for Peter Rowland, said "comfort and ease" for guests is paramount when designing a menu.

"We always design menus for our clients who host cocktail events to avoid foods that take more than two bites, that are overly constructed, for example piled high like Mount Everest and risk collapsing, and that are laden with sauces," he said.

Mr Haigh, who will be behind menus for major events including the Melbourne Cup Carnival for the Victoria Racing Club and the Virgin Australia Melbourne Fashion Festival, said a good rule was nothing bigger than 2.5 centimetres square.

"The food served is always an elegant one mouthful and for extra panache, the base used never leaves a crumb or trace on the fingers," he said.

And what of the oversized canape that practically requires a card table and cutlery to safely navigate?

"For stand-up events, always minimise the use of utensils. It's hard for guests to balance a drink, large plate or bowl and look elegant at the same time and never serve beetroot," Mr Haigh said.

Georgina Damm, of Damm Fine Food Group, has a similar sentiment about so-called "messy" foods, and adds turmeric, saffron and curries to the list.

And those other slippery little suckers: cherry tomatoes.

"Cherry tomatoes must be cut – I have seen so many people cut into a tomato and it flies across the room, or seeds go everywhere."