Some tickets - such as https://bugs.kde.org/show_bug.cgi?id=397716 - are set to status REOPENED. This status is not defined in https://bugs.kde.org/page.cgi?id=fields.html#bug_status
It means the bug got re-opened. There's nothing confusing about that. What's confusing is why it needs to exist; really no difference between it and REPORTED. But this is an issue for Bugzilla itself to fix.