// Media hooks.
add_filter( 'wp_handle_upload_prefilter', 'check_upload_size'
);
// User hooks.
add_action( 'user_admin_notices', 'new_user_email_admin_notice'
);
add_action( 'network_admin_notices', 'new_user_email_admin_notice'
);
add_action( 'admin_page_access_denied', '_access_denied_splash', 99
);
// Site hooks.
add_action( 'wpmueditblogaction', 'upload_space_setting'
);
// Network hooks.
add_action( 'update_site_option_admin_email', 'wp_network_admin_email_change_notification', 10, 4
);
// Post hooks.