Facebook Inc.’s Oversight Board said the social media company hadn’t been “fully forthcoming” about internal rules that allowed some high-profile users to be exempt from content restrictions and said it will make recommendations on how to change the system. In the first of its quarterly transparency reports published Thursday, the board said that on some occasions, Facebook “failed to provide relevant information to the Board,” and in other instances the information it did provide was incomplete. For example, when Facebook referred the case involving former President Donald Trump to the board, it didn’t mention its internal “cross-check system” that allowed for a different set of rules for high-profile users.