Selfies are "not possible" during Prince William and Kate's official visit through B.C. and Yukon with their children later this month, warns the Department of Canadian Heritage.

Her Majesty the Queen is reportedly not a fan of the selfie craze, but the Canadian government says that's not the reason the informal pictures won't be allowed.

They just take too much time.

"To ensure the Duke and Duchess have the opportunity to meet with as many Canadians as possible, it is not possible to take selfies with them," said the Department of Canadian Heritage in a statement.

Those invited to meet the Duke and Duchess of Cambridge directly also won't be allowed "personal photographs," according to the statement.

Of course, if a royal wanders into your selfie, as the Queen did for these Australian field hockey players in 2014, that's another matter.

Other photographs taken in a "respectful and courteous manner" are allowed.

No hats after 6:30 p.m.

Beyond the selfie rules, the heritage department has issued guidelines for people meeting the royal family β€” covering everything from curtseys and toasts to hats and gloves.

These are not inflexible dictums, just tips to make people "feel comfortable and prepared," the site notes.

If you meet Will or Kate, don't call them Will or Kate, but "Your Royal Highness" on first reference. Sir and Ma'am is fine as the conversation continues.

Kate Catherine Duchess of Cambridge

Hats are acceptable, but not required β€” and not generally worn at functions after 6:30 p.m., advises the Department of Canadian Heritage in its advice for meeting royals. Here, the Duchess of Cambridge wears a maple leaf hat for Canada Day in Ottawa in 2011. (Kensington Palace/Twitter)

Those who wish can bow and curtsey or shake hands if the opportunity presents itself and a royal offers their hand.

And as for those hands? There's no requirement for gloves, and they needn't be white.

"Members of the Royal Family do not wish anyone to be put to unnecessary expense by buying special clothes, hats or gloves," according to the site.

Hats are not required, but are "entirely acceptable" in the daytime. "Hats are not normally worn at functions after 6:30 p.m.," the heritage department advises.

And if you wish to avoid clashing with Kate? No, they won't tell you what colour her dress will be.

"It is not generally known in advance what colour clothes Her Majesty or other female Members of the Royal Family will wear at functions."

Royal Tour Canada

Prince William and Kate, the Duke and Duchess of Cambridge, wave as they board their plane to leave Ottawa on July 2, 2011. (Charlie Riedel/The Associated Press)

Royal tour agenda

Will and Kate's itinerary for their trip to B.C. and Yukon. (CBC)

With files from Mike McArthur