What they are, how they work around here
. Can be viewed and accessed by all visitors, not needing to be logged in.
.. Can be accessed and viewed by registered accounts only
... Can be considered moderation content
.... Can follow as a web-administration level of access.
..... Is about as good at it gets with regards to domain control on a front end level.
There may be sub categories inside of each main category, these sub categories will follow much the same 1-5 period rule in their permissions and access or control, and again possibly each having it's own.