This is a special group literally all users belong. The main use of this group is to lift a web level restriction at the topic level.
This is close to
AllAuthUsersGroup. The difference is that unauthenticated users belong to
AllUsersGroup but not to
AllAuthUsersGroup.
Let's say a web is viewable only by the members of the DarkSideGroup by the following line on WebPreferences.
* Set ALLOWWEBVIEW = Main.DarkSideGroup
By putting the following line on a topic, you can make it viewable by anybody.
* Set ALLOWTOPICVIEW = Main.AllUsersGroup
This topic is not necessary for the group to work because the group is implemented in the code instead of a topic that has members.
Related topics:
TWikiAccessControl,
AllAuthUsersGroup