Facebook Inc.'s /zigman2/quotes/205064656/composite FB -0.46% oversight board said Thursday that the social-media company has "not been fully forthcoming" when it comes to providing the board with information about its "crosscheck" system, through which the company is said to have held higher-profile users to different standards when it comes to enforcement of Facebook rules. Following a Wall Street Journal investigation into the cross-check system , Facebook's oversight board began looking into the program and found that Facebook sometimes "failed to provide relevant information." In other cases the company provided incomplete information. The oversight body said in a Thursday blog post that it has accepted a request from Facebook to review the crosscheck system and provide recommendations on potential changes. "Specifically, Facebook requested guidance on, among other things: how to ensure fairness and objectivity in cross-check reviews, taking into account context; how to govern cross-check and promote transparency; and the criteria it uses to determine who is included in cross-check and how to ensure this is equitable," according to the blog post. Shares of Facebook have gained 25% so far this year as the S&P 500 /zigman2/quotes/210599714/realtime SPX +1.14% has risen 21%.