The "Unread Posts / Unread Subforum Posts / No Unread Posts" behavior doesn't seem to work right (at least for me - *buntu 14.04 using Chrome 48.0.2564.116 64-bit). Typically, if there are no unread posts in the parent forum, but unread posts in the child forum, the icon is only half shaded/lit. With the "Service Announcements" board, however, the icon is fully lit even if there are only posts in the child/sub-forum.
Just a minor annoyance to those of us who would like to ignore the "Micro" sub