definition
strict definition
root definition
This term is necessary and is used to organize connected definitions such as attributes, metadata, and objects. It's not intended for organizing data.
The root definition is the top of the definition tree. Every other term hangs beneath it, either directly or through a chain of parents.
It holds the tree together and describes nothing in the world. Attributes, metadata and objects are the branches organized under it.
Nothing should be filed against it as data. A value that ends up on the root is a term whose real parent was never picked, and it belongs one or more levels further down.