Joomla! 3.5.1 joomsocial custom preferences

Question

I am using Joomla! 3.5.1 and joomsocial custom preferences.

My code for viewing the preferences

$currentUser = CFactory::getUser();
print "<pre>"; 
print_r( $currentUser );

output

CUser Object
(
[_userid] => 1071
[_status] => 
[_cparams] => CParameter Object
    (
        [_xml:protected] => 
        [data:protected] => stdClass Object
            (
                [notifyEmailSystem] => 1
                [privacyProfileView] => 0
                [privacyPhotoView] => 0
                [privacyFriendsView] => 0
                [privacyGroupsView] => 
                [privacyVideoView] => 0
                [notifyEmailMessage] => 1
                [notifyEmailApps] => 1
                [notifyWallComment] => 0
                [notif_groups_notify_admin] => 1
                [etype_groups_notify_admin] => 1
                [notif_user_profile_delete] => 1
                [etype_user_profile_delete] => 1
                [notif_system_reports_threshold] => 1
                [etype_system_reports_threshold] => 1
                [notif_profile_activity_add_comment] => 1
                [etype_profile_activity_add_comment] => 1
                [notif_profile_activity_reply_comment] => 1
                [etype_profile_activity_reply_comment] => 1

Question:

I would like to know about these preferences

            [notifyEmailSystem] => 1
            [privacyProfileView] => 0
            [privacyPhotoView] => 0
            [privacyFriendsView] => 0
            [privacyGroupsView] => 
            [privacyVideoView] => 0
            [notifyEmailMessage] => 1

Where thse are storing in database? How I can add further more custom preferences?