The Baghdad Rules is an ancient, fifty-volume, leather bound book on everything of interest to the djinn, including their laws and limitations. It is from here that the Blue Djinn of Babylon derives her power and enforces justice to the djinn.
The Baghdad Rules allows body-borrowing but forbids body-snatching, unless the body is not being used. Despite this, several times in the book, evil tribes such as the Ifrit abuse this rule.
Another rule presented in the Baghdad Rules is that a djinn cannot wish for what they do not know, only for what is known to them. This is a distinction that is difficult for some to grasp.