Kate Middleton can't sign an autograph: Bizarre rules royal family must follow

Royal Family: Here are 6 other bizarre rules that the royal family must follow

As Prince William's wife Kate Middleton made a surprise appearance at the Chelsea Flower Show, she declined to sign her autograph for young fans due to a little-known rule within the royal family. Kate Middleton said, "My name’s Catherine. I’m not allowed to write my signature, it’s just one of those rules." Here are 6 other bizarre rules that the royal family must follow:

Britain's Kate, The Princess of Wales, Patron of the Foundling Museum, waves as she arrives to visit the Museum in London. (AP)

1. No one can touch them

The public is not allowed to touch royal family members. The royal family's official website states that there are "no obligatory codes of behaviour" when meeting the King, Camilla or any member of the royal family but there are some “traditional forms” of behaviour that apply. Men are encouraged to do a "neck bow" and women a “small curtsy” when they meet the royal family.

2. No PDA (Public display of affection)

Members of the royal family are expected to refrain from any form of PDA as they are expected to maintain proper decorum when they are out in public view.

3. Royal heirs travel separately

Royal heirs to the throne are not supposed to travel together in order to protect the line of succession. Two direct heirs - like Prince William and Prince George - are not allowed to travel together- based solely on security and securing the monarchy.

4. Royals must carry an all-black outfit when travelling

The reasoning behind this one is in case someone dies. Royal family hopes to be prepared in such an event which is why they pack an all-black outfit at all times while travelling.

5. Royals must accept all gifts gracefully

This rule states that members of the royal family must accept any gifts that they receive during royal engagements and official tours. But the monarch gets to decide which royals keep which gift.

6. Only married women wear crowns

Only married women are allowed to wear a tiara to most formal occasions, however, the decision to wear the expensive headpiece, is based on the wearer's personal preference and the dress code of the event they are attending.