Master account and sub account holders can limit how visible they are to other users on PlayStation Network and who they receive communications from using ‘Privacy Settings’. The aspects that can be altered include the following:
If you are a master account holder you cannot set parental controls on your associated sub accounts to limit the aspects of PlayStation Network listed above. Privacy Settings can only be changed through the sub account itself.
Please note that selecting ‘No One’ will mean that you will not receive any invitations or requests from any PlayStation Network users, including those on your Friends List.