It's understood that new rules were created in attempts to defend Meghan and Kate amidst reams of online trolling.
The royal family has published new rules for followers engaging with its official social media accounts, in the wake of online abuse directed at the Duchesses of Sussex and Cambridge.
The social media community guidelines published on the royal family's official website state that comments left on its feed must not "be defamatory of any person, deceive others, be obscene, offensive, threatening, abusive, hateful, inflammatory or promote sexually explicit material or violence".
Additionally, comments that "promote discrimination based on race, sex, religion, nationality, disability, sexual orientation or age" will not be tolerated.
The new guidelines follow reports that palace staff were being forced to spend several hours each week deleting abusive posts from the royal family's official Instagram and Twitter accounts.
A report in The Guardian in January said the palace had sought advice from social media giant Instagram on dealing with the hateful comments, which are said to have included physical threats.
The new guidelines state that where appropriate abusive comments will be forwarded to the police for investigation.
"We also reserve the right to send any comments we deem appropriate to law enforcement authorities for investigation as we feel necessary or is required by law."
It's understood that the vast majority of abuse is being directed at the two wives of William and Harry, given their growing presence on social media and in the public eye.
Markle, a Hollywood actress and former lifestyle blogger, with a substantial social media following of her own, closed her personal accounts when her relationship with Prince Harry became serious.
Markle is due to give birth this spring.