PAM_FAIL_DELAY A function pointer to redirect centrally managed failure delays. See pam_fail_delay3 . PAM_XDISPLAY The name of the X display. For graphical, X-based applications the value for this item should be the $DISPLAY variable. This value should be used instead of PAM_TTY for passing the name of the display where possible. PAM_XAUTHDATA A pointer to a structure containing the X authentication data required to make a connection to the display specified by PAM_XDISPLAY, if such information is necessary. See pam_xauth_data3 .