The gametree serves a dual purpose; it acts as a storage for the user data, typically in the form of character sheets but also various other things, and it also acts as a definition of two distinct user interfaces to that data. The main user interface it supports is the "Use" dialog. This brings up a dialog which contains a node and all of its children in a way that enables ease of reading the data and sending things such as die rolls to chat. The other user interface is the tree's display within the window. This is the "raw" user interface where each node is directly accessed but it is required for the initial creation of the character sheets and so on and has all the character sheet authoring functionality.
The tree is used three times,
Node Types