Meghan Markle is reportedly being given a crash course in a bewildering array Royal etiquette as her much anticipated royal wedding with Prince Harry looms.

Along with what to wear and when, the US actress must learn the intricacies of who among her new future in-laws she needs to curtsey to, and who she doesn’t.

Meghan is reportedly studying the royal rule book, Precedence Of The Royal Family To Be Observed At Court, first drawn up to avoid confusion when Prince Charles married Camilla Parker Bowles in 2005.

The tome was updated in 2012 when Prince William married Kate, and is expected to again be updated after Harry marries Meghan in May, Myka Meier, founder and director of Beaumont Etiquette, told People magazine.

Under the rules, Meghan need to curtsy to Queen Elizabeth and Prince Philip, as well as Charles and Camilla and William and Kate, due their position in line for the throne.

Things become more complicated when it comes to the extended family.

Meghan is expected to show deference to princesses born into the royal family, including Princess Anne, Princess Alexandra, and Prince Andrew’s daughters Princesses Beatrice and Eugenie – but only if Harry is not around.

If Harry is present, their roles are reversed and the royal princess need to curtsy to Meghan.

Meghan will also have to curtsy to Prince Edward and his wife Sophie, the Countess of Wessex, but only when Sophie is physically with her husband.

Harry has been running through the rules with Meghan, with TMZ reporting the studies began months before the royal engagement was announced late November.

As well as learning the pecking order, Meghan is learning the dos and don’ts when it comes to meeting the public.

On her first official engagement with Harry last week, she was heard turning down selfies with excited onlookers, explaining royals were “not allowed to do selfies”.

Harry’s late mother Princess Diana ran afoul of the rules soon after marrying Charles when she wore a revealing black gown to an official event with Princess Grace.

She was reportedly told that the royal family reserves all black outfits for funerals and mourning.