To find out more about Altopedia, see Altopedia:About.
A really, really quick explanation of namespaces: they're 'sub-area's' of the site that allow us to group content together by relevance (for example all of the Alternative Playground information can be contained in one space, likewise all the OPA information). This makes maintaining the site easier as we can have duplicate names of pages (such as Alternative Playground:Help and Online Press Association:Help) and allows us to set up permissions by namespace so 'page owners' of one namespace can have more control over how they want their area run without impacting other parts of the site.
Here are some of my (TBC's) initial thoughts on how the permissions will be set up on Altopedia (don't worry if it doesn't all make sense yet)
A visitor can view any page that has not been specifically 'hidden' by an 'administrator' or a 'namespace owner'. Note that regardless of how pages are 'hidden' or not, no security is guaranteed.
Users can view any page, not specifically hidden (as above for visitors) and can create/edit any page that is not in a specific namespace.
These users are just like any other User; however they have also registered for edit access within one or more namespaces (this registration is approved by the appropriate namespace owner(s). This means they get read-only access to most of the site and create/edit in certain specific areas (as well as any area that isn't controlled).
These users have the same permissions as namespace users; however they also have more control over the content within the namespace (they can delete pages for example) and can control who has access to what within the namespace. They still have no additional control outside of their namespace.
Administrators have most of the flexibility in what they can do, they can operate on any namespace, they can modify any users' permissions, but there are still some things they can not do (for example password resets for other users).
Other permission profiles will be set up and used as appropriate.