The guidelines have been published on the Royal Family's official website, to "help create a safe environment" where "our community can engage safely in debate and is free to make comments, questions and suggestions".
Anyone who posts obscene, offensive or unintelligible content now runs the risk of being deleted, blocked or subject to legal proceedings in the most significant measures yet to protect the mental health and wellbeing of followers.
By engaging with our social media channels you agree to follow these guidelines.
Australia loses final-over thriller against India after batting collapse
Virat Kohli was man of the match for his 40th hundred, nine less than Sachin Tendulkar's ODI record. Kohli had to dig deep and combined for 67 with Ravindra Jadeja to take India past 200 in the 39th.
In an unprecedented statement, he lashed out at the media for racist, sexist and slanderous coverage of his soon-to-be Duchess, but that just seemed to increase a groundswell of the hashtag #Megxit, a hashtag used by twitter conspiracy theorists who believe the Duchess' pregnancy is a hoax.
They didn't mention any royal in particular, but a significant amount of online hate is targeted at Meghan and the new guidelines echo Prince Harry's now-famous statement he issued in 2016 in defence of his then-girlfriend.
In addition, comments centred around the discrimination of race, sex, religion, nationality, disability, sexual orientation or age will not be tolerated.
Should anyone breach those conditions, the royals won't hesitate to delete their comments, kick the offender off their channels, or " send any comments we deem appropriate to law enforcement authorities for investigation as we feel necessary".