The Sakai Encyclopedia is a living, breathing collection of documents and articles. Over time, some of this information will be obsolete with respect to the latest release of Sakai. Since not everyone will be using the latest release of Sakai, older information will be moved to branches of the encyclopedia associated with that particular release.
These release pages also include release notes, descriptions of problems and work arounds, etc. Future releases will contain descriptions of expected features and the like.
Support for releases is subject to the availability of community and volunteer resources to effect that support. Generally this will include the current release and prior releases for which there is a sufficiently large community of folks still running a particular release in production.